The role of African states in the development of the law of the sea at the third United Nations conference

Abstract

This interpretation of the role of African states in the development of the law of the sea at UNCLOS III analyzes relevant economic and political factors behind policy decisions. First, an analysis is made of the economic factors. The African states are developing states and share the common problems of lack of financial resources, dependence on raw material exports, and lack of managerial and technical skills. As members of the Group of 77, they adopt a common approach to the powers of the International Sea‐bed Authority, the economic zone, scientific research, and transfer of technology. However, there are great divergencies among the African states in natural resources and rate of development; divergent interests have emerged between the coastal states and the landlocked ones, and these differences are reflected in negotiating positions. The major political element dominating the approach of the African states is the colonial heritage of the great majority and their becoming independent in the period between the 1958/60 Conferences and UNCLOS III. This common political background has contributed to the strong cohesion of the African Group and its adherence to a group position throughout the negotiations, despite the divergent economic interests of individual states.

The positions of the African states are analyzed in depth, from the Sea‐bed Committee through the 6th Session of UNCLOS III. One of the major contributions made by the African states to the law of the sea is the development of the economic zone concept, which is essentially different from the extension of the territorial sea proposed by some other developing states, and from the continental shelf concept. The African provision made for participation by landlocked states in access to the living resources of the zone is also an important innovation, which promises a radically new approach to resource management. Finally, the impact made by the African states is examined in the context of the development of a New Economic Order. The law of the sea is seen as one aspect of the global problem of allocating benefits from world resources towards the developing states, and redressing the balance between the industrialized and the developing nations.     

A model of cell firing patterns during epileptic seizures

A simplified model is presented of the dynamics of excitatory and inhibitory neurons in the cerebral cortex. A key feature of the model is that neurons may cease to fire when strongly depolarized (spike inactivation). Computer simulations for different parameters reveal five classes of solutons: a) steady states in which neither excitatory nor inhibitory cells are active, b) steady states in which one or both types of cells fire repetitively, c) states in which one type of cell fluctuates rapidly between bursts of action potentials and inactivity due to strong depolarization, d) rhythmic activity in which both types of cells fire in unison followed by a period of spike inactivation and e) states similar to d but in which the inhibitory cells never produce action potentials. Solutions b, c, d, and e qualitatively resemble the different firing patterns observed during experimental seizures. It is shown that changes in those parameters that are functions of potassium concentration can induce changes in the type of solution. It is therefore proposed that the increase in extracellular potassium concentration during seizures may be responsible for the progressive changes observed in firing patterns and particularly for the transition from tonic to clonic patterns. A method is also outlined for testing the predictions of the model.     

Primary Hyperparathyroidism and Vitamin D In African Americans

ObjectivesVitamin D deficiency is more common in African Americans than in the general population or other ethnicities. Vitamin D deficiency also occurs more frequently in patients with primary hyperparathyroidism (PHPT) than in the general population. Currently, the limited data on vitamin D deficiency in African Americans with primary hyperparathyroidism (PHPT) is inconsistent as to whether the vitamin D deficiency observed in PHPT is yet even more pronounced in Africans with PHPT relative to non-African Americans with PHPT.MethodsOn the basis of biochemical, radiological, and surgical (adenoma weight) parameters, African Americans have been reported to have a more severe form of PHPT than non-African Americans. However, comparative clinical manifestations of PHPT in African Americans have not been well described.ResultsCurrent guidelines recommend vitamin D repletion in mild, asymptomatic PHPT when levels of 25-hydroxyvitamin D are less than 20 ng/mL. Studies that reported vitamin D repletion with ergocalciferol or cholecalciferol in PHPT have not stratified data according to ethnicity. Discrepancies therefore exist between repleting vitamin D in African Americans who may potentially have a more severe PHPT profile, but simultaneously a more pronounced vitamin D deficiency.ConclusionEffectively designed clinical trials are necessary to evaluate the indications, efficacy, and safety of vitamin D in African Americans with PHPT. (Endocr Pract. 2012;18:947-953)     

Prevalence of anxiety and depressive illness and help seeking behaviour in African Caribbeans and white Europeans: two phase general population survey

ObjectiveTo determine the prevalence of common mental disorders (anxiety and depression) and help seeking behaviour in African Caribbeans and white Europeans.DesignTwo phase survey in a general population sample. The first phase comprised screening with the 12 item general health questionnaire; the second phase was standardised psychiatric assessment and interview about help seeking.SettingPeople registered with four general practices in central Manchester.ParticipantsOf 1467 people randomly selected from family health services authority lists, 864 were still resident. 337 African Caribbeans and 275 white Europeans completed the screening phase (response rate 71%); 127 African Caribbeans and 103 white Europeans were interviewed in the second phase.Results13% of African Caribbeans (95% confidence interval 10% to 16%) and 14% (10% to 18%) of white Europeans had one or more disorder. Anxiety disorders were significantly less common among African Caribbeans (3% (1% to 5%) v 9% (6% to 12%) in white Europeans). Depressive disorders were significantly more common among African Caribbean women than white women (difference 8% (1% to 15%)). Medical help seeking was similar in the two groups, but African Caribbeans with mental disorders were more likely to seek additional help from non-medical sources (12/29 v 5/29, P=0.082).ConclusionsIn an inner city setting the prevalence of common mental disorders is similar in these two ethnic groups.

Key messages

• Most studies of ethnic differences in mental health focus on psychotic illness rather than common mental disorders
• In this inner city study the prevalence of anxiety and depression was similar in African Caribbeans and white Europeans
• Anxiety disorders were less common, and depression more common, in African Caribbeans than white Europeans
• Improved recognition and treatment of non-psychotic disorders are necessary, taking into account patients’ views of their illnesses

     

Migrant African women: tales of agency and belonging

Abstract

This paper explores issues of belonging and agency among asylum seekers and refugee women of African origin in the UK. It discusses the ways these women engendered resistance in their everyday life to destitution, lack of cultural recognition, and gender inequality through the foundation of their own non-governmental organization, African Women's Empowerment Forum, AWEF, a collective ‘home’ space.

The focus of this account is on migrant women's agency and self-determination for the exercise of choice to be active actors in society. It points to what might be an important phenomenon on how local grassroots movements are challenging the invisibility of asylum seekers’ and refugees’ lives and expanding the notion of politics to embrace a wider notion of community politics with solidarity.

AWEF is the embodiment of a social space that resonates the ‘in-between’ experience of migrant life providing stability to the women members regarding political and community identification.     

African Rice (<Emphasis Type="Italic">Oryza glaberrima</Emphasis> Steud.): Lost Crop of the Enslaved Africans Discovered in Suriname<Superscript>1</Superscript>

African Rice ( Oryza glaberrima Steud.): Lost Crop of the Enslaved Africans Discovered in Suriname. African rice (Oryza glaberrima Steud.) was introduced to the Americas during the slave trade years and grown by enslaved Africans for decades before mechanical milling devices facilitated the shift towards Asian rice (O. sativa L.). Literature suggests that African rice is still grown in Guyana and French Guiana, but the most recent herbarium voucher dates from 1938. In this paper, evidence is presented that O. glaberrima is still grown by Saramaccan Maroons both for food and ritual uses. Saramaccan informants claim their forefathers collected their first “black rice” from a mysterious wild rice swamp and cultivated these seeds afterwards. Unmilled spikelets (grains with their husk still attached) are sold in small quantities for ancestor offerings, and even exported to the Netherlands to be used by Maroon immigrants. Little is known of the evolution of O. glaberrima, before and after domestication. Therefore, more research is needed on the different varieties of rice and other “lost crops” grown by these descendants of enslaved Africans who escaped from plantations in the 17th and 18th centuries and maintained much of their African cultural heritage in the deep rainforest.     

Further studies of some aspects of a neurobiophysical model of schizophrenia

The neurobiophysical model of schizophrenia discussed previously (Bull. Math. Biophysics,26, 167–185, 1964;27, 21–26, 1965) is generalized further, to include catatonic and stuporous states. It is concluded that the development of schizophrenia will proceed through different stages of catatonic and non-catatonic states, depending on parameters which characterize on one hand the general inhibition of the individual, on the other hand what may be called his “stability.” Suggestions for possible clinical verifications of the conclusions are made.     

An Extended Gibbs Ensemble

Abstract

A general extended Gibbs ensemble, obtained by augmenting the standard Gibbs ensemble by intermediate states in the spirit of the scaled particle method of Nezbeda and Kolafa [Molec. Simul., 5, 391 (1991)], is introduced. The intermediate states span the states with different number of particles in the simulation boxes and facilitate the transfer of particles even in such complex systems as e.g., mixtures of very different components, systems of flexible polymeric molecules, or systems at very high densities. A general formulation of the ensemble is given and two implementations are considered in detail. The method is very general and is exemplified by studying the fluid-fluid coexistence in a dense binary mixture of the hard-sphere and square-well fluids. It is found that its efficiency is about by factor three greater in comparison with the standard Gibbs ensemble simulations.     

The Incidence Patterns Model to Estimate the Distribution of New HIV Infections in Sub-Saharan Africa: Development and Validation of a Mathematical Model

BackgroundProgrammatic planning in HIV requires estimates of the distribution of new HIV infections according to identifiable characteristics of individuals. In sub-Saharan Africa, robust routine data sources and historical epidemiological observations are available to inform and validate such estimates.ConclusionsIt is possible to reliably predict the distribution of new HIV infections acquired using data routinely available in many countries in the sub-Saharan African region with a single relatively simple mathematical model. This tool would complement more specific analyses to guide resource allocation, data collection, and programme planning.     

Application of Framingham risk estimates to ethnic minorities in United Kingdom and implications for primary prevention of heart disease in general practice: cross sectional population based study

ObjectiveTo compare the 10 year risk of coronary heart disease (CHD), stroke, and combined cardiovascular disease (CVD) estimated from the Framingham equations.DesignPopulation based cross sectional survey.SettingNine general practices in south London.Population1386 men and women, age 40-59 years, with no history of CVD (475 white people, 447 south Asian people, and 464 people of African origin), and a subgroup of 1069 without known diabetes, left ventricular hypertrophy, peripheral vascular disease, renal impairment, or target organ damage.ResultsPeople of African origin had the lowest 10 year risk estimate of CHD adjusted for age and sex (7.0%, 95% confidence interval 6.5 to 7.5) compared with white people (8.8%, 8.2 to 9.5) and south Asians (9.2%, 8.6 to 9.9) and the highest estimated risk of stroke (1.7% (1.5 to 1.9), 1.4% (1.3 to 1.6), 1.6% (1.5 to 1.8), respectively). The estimate risk of combined CVD, however, was highest in south Asians (12.5%, 11.6 to 13.4) compared with white people (11.9%, 11.0 to 12.7) and people of African origin (10.5%, 9.7 to 11.2). In the subgroup of 1069, the probability that a risk of CHD ⩾15% would identify risk of combined CVD ⩾20% was 91% in white people and 81% in both south Asians and people of African origin. The use of thresholds for risk of CHD of 12% in south Asians and 10% in people of African origin would increase the probability of identifying those at risk to 100% and 97%, respectively.ConclusionPrimary care doctors should use a lower threshold of CHD risk when treating mild uncomplicated hypertension in people of African or south Asian origin.     

A systematic review and meta-analysis of the aetiological agents of non-malarial febrile illnesses in Africa

BackgroundThe awareness of non-malarial febrile illnesses (NMFIs) has been on the rise over the last decades. Therefore, we undertook a systematic literature review and meta-analysis of causative agents of non-malarial fevers on the African continent.MethodologyWe searched for literature in African Journals Online, EMBASE, PubMed, Scopus, and Web of Science databases to identify aetiologic agents that had been reported and to determine summary estimates of the proportional morbidity rates (PMr) associated with these pathogens among fever patients.FindingsA total of 133 studies comprising 391,835 patients from 25 of the 54 African countries were eligible. A wide array of aetiologic agents were described with considerable regional differences among the leading agents. Overall, bacterial pathogens tested from blood samples accounted for the largest proportion. The summary estimates from the meta-analysis were low for most of the agents. This may have resulted from a true low prevalence of the agents, the failure to test for many agents or the low sensitivity of the diagnostic methods applied. Our meta-regression analysis of study and population variables showed that diagnostic methods determined the PMr estimates of typhoidal Salmonella and Dengue virus. An increase in the PMr of Klebsiella spp. infections was observed over time. Furthermore, the status of patients as either inpatient or outpatient predicted the PMr of Haemophilus spp. infections.ConclusionThe small number of epidemiological studies and the variety of NMFI agents on the African continent emphasizes the need for harmonized studies with larger sample sizes. In particular, diagnostic procedures for NMFIs should be standardized to facilitate comparability of study results and to improve future meta-analyses. Reliable NMFI burden estimates will inform regional public health strategies.     

Incidence,mortality and receptor status of breast cancer in African Caribbean women: Data from the cancer registry of Guadeloupe

BackgroundGeographical disparities in breast cancer incidence and outcomes are reported worldwide. Women of African descent show lower incidence, higher mortality rates and earlier age of onset. We analyzed data from the cancer registry of Guadeloupe for the period 2008–2013.MethodsWe describe breast cancer characteristics by molecular subtype, as well as estimated observed and net survival. We used Cox proportional hazard models to determine associations between cancer subtypes and death rate, adjusted for variables of interest.ResultsOverall, 1275 cases were recorded with a mean age at diagnosis of 57(±14) years. World standardized incidence and mortality were respectively 71.9/100,000 and 14.1/100,000 person-years. Age-specific incidence rates were comparable to European and US populations below the age of 45, and higher in Guadeloupean women aged between 45 and 55 years. Overall, 65.1% of patients were hormone receptor (HR)+ and 20.1% were HR-. Triple negative breast cancers (TNBC) accounted for 14% of all cases, and were more frequent in patients under 40 (21.6% vs. 13.4%, p = 0.02). Five-year net survival was 84.9% [81.4-88.6]. It was higher for HR+/Her2+ and HR+/Her2- subtypes, and lower for HR-/Her2+ and TNBC patients.ConclusionWe found high age-specific incidence rates of breast cancer in women aged 45 to 55 years, which warrants further investigation in our population. However, this population of mainly African descent had good overall survival rates, and data according to subtypes are consistent with those reported internationally. These results may suggest that poorer survival in other African descent populations may not be an inherent feature of the disease but may be amenable to improvement.     

Race/Ethnicity-Specific Association of Vitamin D and Global DNA Methylation: Cross-Sectional and Interventional Findings

ObjectivesUnderstanding of the influence of vitamin D deficiency on epigenome will provide novel insights into the chronic disease risk. We tested our hypotheses that 1) vitamin D deficiency is associated with global hypomethylation and this association may be race/ethnicity dependent; and 2) vitamin D supplementation will increase global DNA methylation level.MethodsA two-stage design, cross-sectional observation followed by a 16 week randomized, double- blinded, placebo-controlled trial (RCT) of vitamin D3 supplementation, was undertaken. Global DNA methylation level (percentage of 5-methylcytosine, %5-mC) was quantified using leukocyte DNA with the MethylFlash^TM Methylated DNA Quantification kit (Epigentek). Global methylation data was obtained from 454 Caucasians and African Americans (42%) in the observation cohort and 58 African Americans with vitamin D deficiency in the dose responsive RCT.ResultsIn the cross-sectional study, African Americans had lower %5-mC than Caucasians (P = 0.04). A significant interaction was detected between plasma 25(OH)D and race on %5-mC (P = 0.05), as a positive association was observed between plasma 25(OH)D and %5-mC in African Americans (β = 0.20, p<0.01), but not in Caucasians (β = 0.03, p = 0.62). In the 16-week RCT, a dose-response benefit of vitamin D₃ supplementation was observed for %5-mC, as indicated by a significant linear upward trend (-0.01 ± 0.01%, placebo; 0.11 ± 0.01%, ~600 IU/day; 0.30 ± 0.01%, ~2,000 IU/day; and 0.65 ± 0.01%, ~4,000 IU/day group; P-trend = 0.04).ConclusionsVitamin D deficiency is associated with global hypomethylation in African Americans. Vitamin D3 supplementation increases global DNA methylation in a dose-response manner in African Americans with vitamin D deficiency.     

Low Urine Calcium Excretion in African American Patients with Primary Hyperparathyroidism

ObjectiveTo evaluate the prevalence of low urine calcium excretion in African American patients with primary hyperparathyroidism (PHPT), a common disorder associated with bone and renal complications, and to assess the distinction between PHPT and familial hypocalciuric hypercalcemia (FHH), a rare benign genetic disease.MethodsWe conducted a retrospective study on a cohort of 1,297 patients in whom a 24-hour urine study was performed for measurement of urine calcium and creatinine. PHPT was diagnosed if the serum calcium concentration was ≥ 10.5 mg/dL and intact parathyroid hormone (PTH) was ≥ 40 pg/mL. Patients receiving medications that affect urine calcium or with glomerular filtration rate ≤ 30 mL/min were excluded.ResultsNinety-six patients satisfied the diagnostic criteria for PHPT. The African American (n = 70) and non-African American (n = 26) patients did not differ in their mean age, body mass index, glomerular filtration rate, serum PTH, 25-hydroxyvitamin D levels, and 24-hour urine creatinine values. Median values of urine calcium/creatinine (mg/g) were 122 for African American versus 214 for non-African American patients (P = .006). Thirty-one of 70 African American patients (44%) had a urine calcium/creatinine ratio ≤ 100 mg/g, whereas only 2 of 26 non-African American patients (8%) had this value (P = .001).ConclusionThe prevalence of low urine calcium excretion among African American patients with PHPT is unexpectedly high. A threshold of 100 mg/g urine calcium/ creatinine identified 44% of such patients with PHPT as having FHH in this cohort. Therefore, other clinical criteria and laboratory variables should be used to distinguish PHPT from FHH in African American patients with PTH-dependent hypercalcemia. (Endocr Pract. 2011;17: 867-872)     

Ethnic differences in guideline-indicated statin initiation for people with type 2 diabetes in UK primary care, 2006–2019: A cohort study

BackgroundType 2 diabetes is 2–3 times more prevalent in people of South Asian and African/African Caribbean ethnicity than people of European ethnicity living in the UK. The former 2 groups also experience excess atherosclerotic cardiovascular disease (ASCVD) complications of diabetes. We aimed to study ethnic differences in statin initiation, a cornerstone of ASCVD primary prevention, for people with type 2 diabetes.Methods and findingsObservational cohort study of UK primary care records, from 1 January 2006 to 30 June 2019. Data were studied from 27,511 (88%) people of European ethnicity, 2,386 (8%) people of South Asian ethnicity, and 1,142 (4%) people of African/African Caribbean ethnicity with incident type 2 diabetes, no previous ASCVD, and statin use indicated by guidelines. Statin initiation rates were contrasted by ethnicity, and the number of ASCVD events that could be prevented by equalising prescribing rates across ethnic groups was estimated. Median time to statin initiation was 79, 109, and 84 days for people of European, South Asian, and African/African Caribbean ethnicity, respectively. People of African/African Caribbean ethnicity were a third less likely to receive guideline-indicated statins than European people (n/N [%]: 605/1,142 [53%] and 18,803/27,511 [68%], respectively; age- and gender-adjusted HR 0.67 [95% CI 0.60 to 0.76], p < 0.001). The HR attenuated marginally in a model adjusting for total cholesterol/high-density lipoprotein cholesterol ratio (0.77 [95% CI 0.69 to 0.85], p < 0.001), with no further diminution when deprivation, ASCVD risk factors, comorbidity, polypharmacy, and healthcare usage were accounted for (fully adjusted HR 0.76 [95% CI 0.68, 0.85], p < 0.001). People of South Asian ethnicity were 10% less likely to receive a statin than European people (1,489/2,386 [62%] and 18,803/27,511 [68%], respectively; fully adjusted HR 0.91 [95% CI 0.85 to 0.98], p = 0.008, adjusting for all covariates). We estimated that up to 12,600 ASCVD events could be prevented over the lifetimes of people currently affected by type 2 diabetes in the UK by equalising statin prescribing across ethnic groups. Limitations included incompleteness of recording of routinely collected data.ConclusionsIn this study we observed that people of African/African Caribbean ethnicity with type 2 diabetes were substantially less likely, and people of South Asian ethnicity marginally less likely, to receive guideline-indicated statins than people of European ethnicity, even after accounting for sociodemographics, healthcare usage, ASCVD risk factors, and comorbidity. Underuse of statins in people of African/African Caribbean or South Asian ethnicity with type 2 diabetes is a missed opportunity to prevent cardiovascular events.

In a retrospective cohort study, Sophie Eastwood and colleagues investigate the association between ethnicity and statin initiation for people with type 2 diabetes in UK.     

Philopotaminae of Madagascar (Trichoptera: Philopotamidae)

The Malagasy fauna includes two genera of Philopotaminae: Wormaldia McLachlan 1865 and an endemic new genus, Ranarijaodes n. gen. The Malagasy and African (sensu stricto) lineages of Wormaldia are distinct. Apomorphic characters (the shape of the phallic apparatus for the African species and the splitting of the median lobe of the tenth tergite for the Malagasy species) confirm their separation. New captures are reported for two of the four previously known species of Wormaldia. Seven new species are described: Wormaldia ambahibeae n. sp., W. faharoa n. sp., W. fahatelo n. sp., W. randriamasimananai n. sp., W. fahefatra n. sp., W. legrandi n. sp. and W. fahadimy n. sp. Ranarijaodes n. gen. is close to Dolophilodes Ulmer 1909. It is described for the three new species Ranarijaodes fiana n. sp., R. angapi n. sp. and R. atsimo n. sp. The 14 Malagasy species of Philopotaminae are endemics of the island. Their geographical distributions and ecological preferences are described and discussed.     

NUTRIENTS IN AFRICAN LAKE ECOSYSTEMS: DO WE KNOW ALL?

SUMMARY

It is nearly sixty years since the first studies were undertaken on the nutrient chemistry of African lakes. There have been numerous studies on the chemical composition of African waters in the intervening years. Yet as recently as five years ago it was stated that little was known about nutrient cycling in lakes. Nutrient ‘species’ simply formed an additional list compiled along with lists of species of algae, zooplankton, aquatic plants and fish. A spate of monographs, papers and reports in recent years, however, has begun to fill some of the gaps in our knowledge of nutrient cycling in African lake ecosystems. This paper reviews the recent literature of nutrients in African lakes from the point of view of nutrient sources, in-lake nutrient kinetics and nutrient sinks, with particular reference to nitrogen and phosphorus, and their cycling rates into and out of various biotic and abiotic compartments. The principle conclusions that can be drawn from the review are as follows:

1. Allochthonous inputs, particularly in terms of external nutrient loading, have been relatively well-studied in recent years, but little is known of autochthonous nutrient inputs, despite numerous observations that nutrient regeneration is likely to be substantial in African lakes.

2. The rôle of microbial processes in nutrient cycling in African lakes is almost totally unknown, except in relation to nitrification and denitrification.

3. Recent studies have begun to examine the kinetics of the uptake of phosphorus by algae in African lakes; nitrogen uptake, other than nitrification, and nutrient release have only rarely been examined.

4. Nutrient uptake and release by aquatic macrophytes is reasonably well known, especially in the ‘nuisance’ weed species.

5. The role of zooplankton, zoobenthos and fish in nutrient cycling in African lakes has largely been ignored.

6. A great deal of study has been devoted to the rôle of abiotic process, particularly at the sediment-water interface, in the nutrient dynamics of African lakes.

As yet, little emphasis has been placed on inter-compartmental exchanges in studies on nutrient cycles but it would appear that these processes are now beginning to receive attention and, as nutrient cycling in African lake ecosystems becomes better known, research will tend toward a more numerical approach.     

Relationship between Distinct African Cholera Epidemics Revealed via MLVA Haplotyping of 337 Vibrio cholerae Isolates

BackgroundSince cholera appeared in Africa during the 1970s, cases have been reported on the continent every year. In Sub-Saharan Africa, cholera outbreaks primarily cluster at certain hotspots including the African Great Lakes Region and West Africa.Conclusions/SignificanceTo effectively combat the disease, it is critical to understand the mechanisms of cholera emergence and diffusion in a region-specific manner. Overall, these findings demonstrate the relationship between distinct epidemics in West Africa and the African Great Lakes Region. This study also highlights the importance of monitoring and analyzing Vibrio cholerae isolates.     

Cooperative hunting in a discrete predator–prey system II

ABSTRACT

We investigate a discrete-time predator–prey system with cooperative hunting in the predators proposed by Chow et al. by determining local stability of the interior steady states analytically in certain parameter regimes. The system can have either zero, one or two interior steady states. We provide criteria for the stability of interior steady states when the system has either one or two interior steady states. Numerical examples are presented to confirm our analytical findings. It is concluded that cooperative hunting of the predators can promote predator persistence but may also drive the predator to a sudden extinction.     

基于生物阻抗谱的生物细胞活性免标记检测方法

目的 基于生物阻抗谱（bioelectrical impedance spectroscopy,BIS）技术,提出一种免标记的生物细胞活性实时检测方法。该方法依据不同浓度、生理、病理状态下细胞组织的电学特性差异来判断细胞是否具有活性,以协助医师在临床手术中快速精准定位患者烫伤组织并实现有效切除。方法 使用具有活性的斑马鱼胚胎干细胞来模拟人体烫伤组织,采用生物阻抗谱技术来鉴别细胞组织的生理状态。结果 在不同状态下,细胞的阻抗幅值变化有显著的差异,可以从中发现同等浓度下活性细胞的阻抗幅值比死亡细胞平均高出17.25%,活性细胞发生弛豫频率的时间也比死亡细胞早25%。结论 实验数据表明,生物阻抗谱法能有效区分胚胎干细胞的两类生理状态;从聚类区域中可以看出,BIS检测法具有明显的细胞活性及浓度区分能力,理论上能够快速地协助医师完成对患者烫伤组织检测。