Applicability of the WHO Maternal Near Miss Criteria in a Low-Resource Setting

Background

Maternal near misses are increasingly used to study quality of obstetric care. Inclusion criteria for the identification of near misses are diverse and studies not comparable. WHO developed universal near miss inclusion criteria in 2009 and these criteria have been validated in Brazil and Canada.

Objectives

To validate and refine the WHO near miss criteria in a low-resource setting.

Methods

A prospective cross-sectional study was performed in a rural referral hospital in Tanzania. From November 2009 until November 2011, all cases of maternal death (MD) and maternal near miss (MNM) were included. For identification of MNM, a local modification of the WHO near miss criteria was used, because most laboratory-based and some management-based criteria could not be applied in this setting. Disease-based criteria were added as they reflect severe maternal morbidity. In the absence of a gold standard for identification of MNM, the clinical WHO criteria were validated for identification of MD.

Results

32 MD and 216 MNM were identified using the locally adapted near miss criteria; case fatality rate (CFR) was 12.9%. WHO near miss criteria identified only 60 MNM (CFR 35.6%). All clinical criteria, 25% of the laboratory-based criteria and 50% of the management-based criteria could be applied. The threshold of five units of blood for identification of MNM led to underreporting of MNM. Clinical criteria showed specificity of 99.5% (95%CI: 99.4%–99.7%) and sensitivity of 100% (95%CI: 91.1%–100%). Some inclusion criteria did not contribute to the identification of cases and therefore may be eligible for removal.

Conclusion

The applicability of the WHO near miss criteria depends on the local context, e.g. level of health care. The clinical criteria showed good validity. Lowering the threshold for blood transfusion from five to two units in settings without blood bank and addition of disease-based criteria in low-resource settings is recommended.     

Incidence of near accidental drowsing in locomotive driving during a period of rotation.

The incidence of drowsings as a cause of near traffic accidents was studied on the basis of daily recordings or near accidental events by 288 locomotive drivers during a rotation period of 2-3 weeks. Of 198 near accidents reported during 2,290 trips, 34 cases, or 1,5 cases per 100 trips, were operation missess involving drowsing or strong drowsiness. Improper operation due to drowsing occurred at a certain rate for any group of drivers, irrespective of the type of train, running sections, weather, and other operative conditions such as train delays, whereas 117 cases of danger caused by unforeseen obstacles on the track were related to site characteristics, and 47 cases of other disorders were frequent in unusual operative conditions such as arrival-departure, poor signal display, wrong instructions, or equipment failure. Thus continued driving under ordinary track conditions at a more or less constant speed was likely to induce drowsiness under the dominant influences of fatigue and time of the day; 79% of such cases occurred between midnight and 6 a.m. Most drowsings on the second night appeared during the first 2-4 hr of duty. Effects of monotony and insufficient rest were discussed in relation to recurrent fluctuation in vigilance.     

Chiral aggregates and asymmetric induction of the reduction of prochiral ketones

The aim of this work was to establish structure-reactivity relationships between chiral aggregates (micelles, vesicles, and "pseudo-micelles" of amphiphilic dendrimers) and asymmetric induction. In water, micelles or vesicles formed with sugar-headed surfactants gave less than 10% ee in the reduction of prochiral ketones by NaBH(4), in contrast with dendrimers bearing the same types of sugar moieties, which gave more than 50% ee under the same reaction conditions. Moreover, in the presence of neoglycodendrimers in THF we have been able to improve reduction of prochiral ketones to give very high stereoselectivity, near 100% in many cases. Comparison of these results suggests that to improve high stereoselectivity it is necessary to work with rigid, well-organized colloidal objects. Copyright 2000 Wiley-Liss, Inc.     

许昌市2009—2013年麻疹流行病学特征和监测系统运转状况分析

目的分析许昌市2009—2013年麻疹流行特征和监测系统运转状况,为加速消除麻疹制定策略及措施提供科学依据。方法利用描述性流行病学方法对许昌市2009—2013年麻疹监测系统资料进行统计分析。结果许昌市2009—2013年累计报告麻疹病例675例,年均报告发病率为3.16/10万。全市8个县、市区均有病例报告,病例数主要集中在禹州市,占总病例数的55.56%;发病呈明显的季节性分布,主要集中在2—5月份,占总病例数的73.48%;病例主要集中于0~6岁儿童,占总病例数的85.63%,其中1岁以下婴幼儿占总病例数的50.22%;8月龄~14岁麻疹病例中有确切免疫史者仅占38.58%。随着监测系统及时性和特异性逐年提高,48 h完整调查率由2009年的88.32%上升至2012年的100%;血标本3 d内送达率由2009年的51.68%上升至2013年的100%;实验室结果 7 d内报告率由2009年的52.80%上升至2013年的100%;血标本采集率从2009年48.86%上升至2013年的100%;暴发血清学确诊率、病原学标本采集率均上升至100%。2009—2013年麻疹监测系统敏感性低,排除病例报告发病率为0.49/10万~1.43/10万。结论 2009—2013年许昌市麻疹发病率下降,小年龄组发病构成增加。监测系统运转综合质量逐年提升,但敏感性低。今后应进一步加强麻疹类疫苗接种与管理,提高人群免疫水平;加强医疗机构传染病报告与管理,提高监测系统敏感性,防止传染源扩散。     

2012年广州市荔湾区疑似预防接种异常反应监测情况分析

目的了解广州市荔湾区疑似预防接种异常反应（Adverseevent following immunization,AEFI）监测情况,分析AEFI发生的原因,为改进疫苗质量和提高预防接种服务质量提供依据。方法对2012年荔湾区各预防接种门诊报告的AEFI病例资料进行分析。结果2012年荔湾区开展预防接种的疫苗共82种（不同厂家和剂型）,其中22种疫苗报告AEFI157例。接种共352723剂次,发生率为44．51／10万,其中一般反应、异常反应、偶合症的发生率分别为27．50／10万（占61．78％）、15．88／10万（占35．67％）、11．34／10万（占2．55％）。157例AEFI病例中,0～1岁儿童112例（占71．34％）,0-7岁儿童156例（占99．36％）。AEFI发生率居前的疫苗为七价肺炎球菌结合疫苗、白破疫苗、23价肺炎球菌多糖疫苗,报告发生率分别为253．32／10万、203．94／10万、190．28／10万。结论广州市荔湾区2012年AEFI监测具有较高的覆盖性和灵敏度。荔湾区2012年AEFI以一般反应为主,未发生严重异常反应。加强宣传、加强培训、加强管理,有利于提高预防接种服务的质量。     

Parasites of the black-tailed jackrabbit in north central Colorado.

Forty-four black-tailed jackrabbits, Lepus californicus melanotis Mearns, 1890, were collected near Denver from August, 1972, through July, 1973, and amined for parasites. Recovered parasites and their infection rates were: Eimeria sp. 100%, Cittotaenia sp.27%, coenuri of Multiceps sp. 57%, Cediopsylla inaequalis 14%, Hoplopsyllus affinis 9%, Haemodipsus setoni 2%, Dermacentor andersoni 14%, and Haemaphysalis leporis-palustris 25%.     

Diversity of cultured aerobic organisms in the areas of natural oil seepage on Lake Baikal

The diversity of cultured aerobic organisms collected from water samples and bottom sediment from two areas of natural oil seepage on Lake Baikal has been researched. Representatives of Alpha-, Beta-, and Gammaproteobacteria have been found in samples collected near the Bol’shaya Zelenovskaya River mouth, while near Cape Gorevoi Utes Betaproteobacteria were absent. Most cultures are characterized by a sufficiently high homology level (96–100%) with nucleotide sequences from the international database.     

Efficacy of Bear Deterrent Spray in Alaska

Abstract: We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%), and polar bears (Ursus maritimus; 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears, 20 (28%) black bears, and 2 (3%) polar bears. Red pepper spray stopped bears' undesirable behavior 92% of the time when used on brown bears, 90% for black bears, and 100% for polar bears. Of all persons carrying sprays, 98% were uninjured by bears in close-range encounters. All bear—inflicted injuries (n = 3) associated with defensive spraying involved brown bears and were relatively minor (i.e., no hospitalization required). In 7% (5 of 71) of bear spray incidents, wind was reported to have interfered with spray accuracy, although it reached the bear in all cases. In 14% (10 of 71) of bear spray incidents, users reported the spray having had negative side effects upon themselves, ranging from minor irritation (11%, 8 of 71) to near incapacitation (3%, 2 of 71). Bear spray represents an effective alternative to lethal force and should be considered as an option for personal safety for those recreating and working in bear country. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):640–645; 2008)     

Variability of branching of the a. coeliaca (truncus coeliacomesentericus) in the guinea pig (Cavia aperea f. porcellus)

The authors studied branching of the a. coeliaca (the truncus coeliacomesentericus) in a group of Peruvian short-haired guinea pigs, with special reference to its variability. After the animals had been anaesthetized, their arterial bed was injected with red-dyed latex, fixed and dissected. In all 30 guinea pigs (100%), blood was supplied to the unpaired organs of the abdominal cavity by a truncus coeliacomesentericus arising from the aorta abdominalis at fundus ventriculi level. In 53.3% of the cases, the truncus coeliacomesentericus divided into a truncus gastrolienalis sending out an a. gastrica sinistra and an a. lienalis, and to a truncus hepatomesentericus which split up into an a. hepatica communis and a. mesenterica cranialis. An a. coeliaca (tripus Halleri) was found in only one guinea pig (3.3%), as a branch of the truncus coeliacomesentericus. In the remaining cases, the truncus branched in the most varied ways. The a. gastrica sinistra was most frequently (60%) a branch of the truncus gastrolienalis. In 21 cases (70%) there was a single a. gastrica sinistra and in nine cases (30%) it was doubled. In 29 cases (96.7%) the a. hepatica communis arose from the truncus hepatomesentericus. The classic type of division of the a. hepatica communis to an a. hepatica propria and an a. gastroduodenalis was observed in every case (100%). In 100% of the cases, the a. hepatica propria terminated in a r. dexter and a r. sinister to the liver. An a. cystica, as a direct branch of the a. hepatica propria, was formed in 28 cases (93.3%). In every case (100%) the a. pancreaticoduodenalis cranialis was a branch of the a. gastroduodenalis. An a. gastrica dextra was recorded in only eight cases in the series (26.7%)--in 23.3% as a branch of the a. hepatica propria and in 3.3% as a branch of the a. cystica. Duplication of this artery was found in one case (3.3%). An a. lienalis was found in 28 cases (93.3%), as a direct branch of the truncus gastrolienalis; in two cases (6.7%) it was doubled. An a. gastroepiploica sinistra and a. gastroepiploica dextra were present in 100% of the cases. Inter-organ arterial anastomoses were found in 22 guinea pigs (73.3%)--between the spleen and the stomach (36.7%), between the pancreas and the stomach (10%), between the stomach, spleen and pancreas (10%) and, in the remaining cases, as various combinations of these connections.(ABSTRACT TRUNCATED AT 400 WORDS)     

潍坊市坊子区2009—2013年流行性腮腺炎流行病学特征分析

目的了解潍坊市坊子区2009—2013年流行性腮腺炎流行病学特征,为预防控制流行性腮腺炎提供科学依据。方法对2009—2013年潍坊市坊子区传染病报告信息管理系统流行性腮腺炎报告病例个案资料,采用描述性流行病学方法分析流行性腮腺炎的流行病学特征。结果潍坊市坊子区2009—2013年累计报告流行性腮腺炎病例416例,年平均发病率为20.97/10万。2009—2013年发病率分别为10.03/10万、10.71/10万、10.74/10万、36.63/10万、24.50/10万;男性为28.92/10万,女性为12.93/10万;0~2岁为30.81/10万,3~9岁为125.74/10万,10~24岁为49.11/10万,25~55岁为1.43/10万。病例数最多的是峡山生态发展区98例,占总病例数的23.56%;凤凰、九龙街办均为92例,各占总病例数的22.12%。发病高峰期在每年的3—7月和12月至次年1月。其中,3—7月占63.70%,1月、12月占17.07%;学生占64.66%,幼托儿童占16.11%,散居儿童占12.26%,其他占6.92%;有临床合并症的病例占5.77%,合并脑膜炎者占5.29%;合并胰腺炎者占0.48%。结论潍坊市坊子区2009—2013年流行性腮腺炎发病率逐年上升,今后应针对重点人群和高发季节进一步加强流行性腮腺炎监测和预防控制工作。     

沭阳县2006-2009年急性弛缓性麻痹病例流行病学分析

为了进一步掌握沭阳县急性弛缓性麻痹(AFP)病例流行特征,从而提高AFP病例的监测工作质量。根据AFP病例个案调查表进行统计分析。结果显示,沭阳县2006-2009年AFP病例监测系统共报告AFP患者28例,15岁以下儿童AFP病例年平均报告发病率为2.31/10万,其中0~4岁发病占67.86%,全程免疫占89.29%,地级医院报告病例占32.14%,AFP患者粪便标本采集率为100%。沭阳县AFP病例监测工作的各项监测指标完成情况较好,但存在薄弱环节,建议不断提高基层医务人员的AFP病例的识别能力和报告意识,消除薄弱环节,不断提高AFP监测工作质量。     

Increased blood levels of human S100 in melanoma chick embryo xenografts' circulation

The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short-term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100beta into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft-host interaction concerning adherence of tumors and extravasation of human melanoma cells.     

Increased Blood Levels of Human S100 in Melanoma Chick Embryo Xenografts’ Circulation

The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short‐term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100β into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft–host interaction concerning adherence of tumors and extravasation of human melanoma cells.     

Depth and movement behaviour of the Pacific sleeper shark in the north-east Pacific Ocean

Satellite-linked radio telemetry was used to study the geographic movements and vertical movement behaviour of the Pacific sleeper shark Somniosus pacificus . The fish were tagged near Steller sea lion Eumetopias jubatus rookeries in the Gulf of Alaska during periods when Steller sea lions pups were most vulnerable to predation; when Steller sea lion pups first enter the water (July to August) and when Steller sea lion pups are weaned (April to May). Final locations recovered from most Pacific sleeper sharks (76%) were within 100 km of release locations, 16% were within 100–250 km and 8% were within 250–500 km. The most striking behavioural feature was their extensive, nearly continuous vertical movements. Median daily depth range was 184 m; the most time (61%) was spent between 150 and 450 m, but ascents above 100 m were common (58% of days). Median vertical movement rate was 6 km day⁻¹ and steady. The longest period of continuous vertical movement (> 60 m h⁻¹) was 330 h. Systematic vertical oscillations were most common (60%), followed by diel vertical migrations (25%) and irregular vertical movements (15%). The Pacific sleeper sharks travelled below the photic zone during the day and approached the surface at night. Pacific sleeper sharks appear to employ a stealth and ambush hunting strategy that incorporates slow vertical oscillations to search for prey, and cryptic colouration and cover of darkness to avoid detection by potential prey. The depth and geographic range of Pacific sleeper shark and Steller sea lions overlap near four important Steller sea lion rookeries in the northern Gulf of Alaska, so the potential exists for predation to occur. None of the tissues in the stomachs of the 198 Pacific sleeper sharks collected during a companion diet study, however, were identified as Steller sea lion.     

Fine needle aspiration biopsy in the diagnosis of thyroid nodules

The fine needle aspiration (FNA) biopsies performed on thyroid nodules at Turku University Central Hospital from 1983 to 1988 were reviewed. Of the 1,054 total aspirated nodules, 194 were investigated histologically after thyroid surgery (191 cases) or at autopsy (3 cases). Two cases with an insufficient FNA sample, 4 with an incidental occult papillary carcinoma and 2 cases with carcinoma outside the nodule investigated by FNA biopsy were excluded from the series, leaving 186 histologically confirmed nodules in the final analysis. Three (3%) of the 107 cases with an FNA biopsy diagnosis of benign, 4 (8%) of the 52 with an FNA diagnosis of equivocal, 3 (20%) of the 15 with an FNA diagnosis of suspicious and all 12 (100%) with an FNA diagnosis of malignant were histologically malignant. If only an unequivocally malignant cytologic finding is considered positive, FNA biopsy had a diagnostic specificity of 100%, a sensitivity of 55% and an accuracy of 95% among the histologically confirmed cases. Follow-up revealed no cases of cancer among the 863 thyroids that were not explored surgically. It is concluded that FNA biopsy is a practical method with considerable diagnostic value in the evaluation of thyroid nodules.     

Single endemic genotype of measles virus continuously circulating in China for at least 16 years

The incidence of measles in China from 1991 to 2008 was reviewed, and the nucleotide sequences from 1507 measles viruses (MeV) isolated during 1993 to 2008 were phylogenetically analyzed. The results showed that measles epidemics peaked approximately every 3 to 5 years with the range of measles cases detected between 56,850 and 140,048 per year. The Chinese MeV strains represented three genotypes; 1501 H1, 1 H2 and 5 A. Genotype H1 was the predominant genotype throughout China continuously circulating for at least 16 years. Genotype H1 sequences could be divided into two distinct clusters, H1a and H1b. A 4.2% average nucleotide divergence was found between the H1a and H1b clusters, and the nucleotide sequence and predicted amino acid homologies of H1a viruses were 92.3%-100% and 84.7%-100%, H1b were 97.1%-100% and 95.3%-100%, respectively. Viruses from both clusters were distributed throughout China with no apparent geographic restriction and multiple co-circulating lineages were present in many provinces. Cluster H1a and H1b viruses were co-circulating during 1993 to 2005, while no H1b viruses were detected after 2005 and the transmission of that cluster has presumably been interrupted. Analysis of the nucleotide and predicted amino acid changes in the N proteins of H1a and H1b viruses showed no evidence of selective pressure. This study investigated the genotype and cluster distribution of MeV in China over a 16-year period to establish a genetic baseline before MeV elimination in Western Pacific Region (WPR). Continuous and extensive MeV surveillance and the ability to quickly identify imported cases of measles will become more critical as measles elimination goals are achieved in China in the near future. This is the first report that a single endemic genotype of measles virus has been found to be continuously circulating in one country for at least 16 years.     

Characteristics of lysosomes in the rat placental cells

Six acid hydrolases, cytochrome oxidase, and alkaline phosphatase were demonstrated in 0.25 m sucrose homogenates of rat chorioallantoic placenta. The acid hydrolases were: acid phosphatase, β-glucuronidase, N-acetyl-β-glucosaminidase, β-galactosidase, and acid deoxyribonuclease, showing optimum activity near pH 4.5; cathepsin, with optimum activity near pH 3.6. The free acid hydrolases present in cytoplasmic extracts expressed 20–40% of their total activity. “Total” activity was defined as the enzyme activity observed in the presence of Triton X-100, while “free” activity denoted enzyme activity measured under similar assay conditions except in the presence of sucrose and absence of Triton X-100. The decreased activity or latency in the assays for the free activity of acid phosphatase, acid deoxyribonuclease, and cathepsin persisted after incubation at pH 5 and 37 ° up to an hour. In contrast, this latency did not persist after incubation of the β-glycosidases. Additionally, the free activity of all the designated enzymes of the cytoplasmic extract was in excess of the nonsedimentable activity observed.     

严重急性呼吸综合征冠状病毒2型 IgM / IgG、病毒核酸和白细胞介素6的联合检测在2019冠状病毒病诊断和治疗中的价值

探讨严重急性呼吸综合征冠状病毒2型(severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)免疫球蛋白M(Immunoglobulin M,IgM)/免疫球蛋白G(Immunoglobulin G,IgG)、病毒核酸和白细胞介素6(interleukin 6, IL-6)的联合检测在2019冠状病毒病(coronavirus disease 2019, COVID-19)诊断和治疗中的临床价值。本研究按照《新型冠状病毒肺炎诊疗方案(试行第七版)》的标准收集了93例确诊病例(51例危重型、18例重型,15例轻型和9例普通型)和20例疑似病例(核酸检测阴性但临床症状和CT检测结果均符合标准)。选取110例儿科、妇科、肿瘤、血液和消化等疾病患者并排除COVID-19作为对照组。采用全自动化学发光免疫分析技术和电化学发光技术检测所有研究对象血清中SARS-CoV-2 IgM/IgG和IL-6。用实时荧光定量反转录聚合酶链反应对病例组和对照组的咽拭子进行SARS-CoV-2核酸检测。结果发现,血清IgM、IgG和IL-6在疑似病例中的阳性率分别为85%、75%和0%,在确诊病例中的阳性率分别为98.9%、95.7%和75.2%(其中危重型分别为100%、100%和100%,重型分别为94.4%、100%和97.9%,轻型分别为100%、93.3%和5%、普通型分别为100%、66.7%和0%)。IL-6和 SARS-CoV-2 IgM/IgG表达水平的改变与患者疾病的严重程度存在一定的关联性,差异有统计学意义(χ²＝273.51,χ²＝149.37;P＜0.05)。血清IL-6和SARS-CoV-2 IgM/IgG的联合检测可作为诊断和治疗COVID-19的监测指标,也可作为SARS-CoV-2核酸检测假阴性的有效互补。     

毒性多结节性甲状腺肿的手术术式探讨

目的:探讨毒性多结节性甲状腺肿的手术切除范围,为临床手术治疗毒性多结节性甲状腺肿提供理论依据。方法:收集2006年12月至2011年12月哈尔滨医科大学附属第一临床医学院普外科确诊且进行手术的52例双侧毒性多结节性甲状腺肿患者的临床资料,并按照术式分为次全切除组(24例)和近全/全切除组(28例)。术后通过病理检查观察其合并甲状腺癌的情况,临床观察其是否出现声音嘶哑(喉返神经损伤)和低钙血症(甲状旁腺损伤)情况,并随访患者甲状腺结节和(或)甲状腺功能亢进的复发情况。结果:次全切除组甲状腺癌的检出率为4.2%(1/24),近全/全切除组检出率为7.1%(2/28),两者比较差异无统计学意义(x2=0.02,P0.05);两组患者术后暂时性声音嘶哑发生率分别为4.2%(1/24)、3.6%(1/28),差异无统计学意义(x2=0.37,P0.05),术后暂时性低钙血症发生率分别为4.2%(1/24)、7.1%(2/28),差异亦无统计学意义(x2=0.02,P0.05)。近全/全切除组患者术后无甲状腺结节和(或)甲状腺功能亢进复发,次全切除组患者有5例复发,复发率为20.8%(5/24),两组比较差异有统计学意义(x2=4.28,P0.05)。结论:甲状腺近全/全切除术比次全切除术更能减少毒性多结节性甲状腺肿的复发。     

Metals biosorption by sodium alginate immobilizedChlorella homosphaera cells

Summary Cadmium and zinc biosorption, alone or in combination, was investigated with sodium alginate immobilizedChlorella homosphaera cells. Concentrations ranging from 20.0 to 41.0mg/l cadmium, 75.0 and 720.0mg/l zinc were tested and, in all cases, the metal removal achieved values near 100%. When these metals were put in combination a decrease in the rate of absorption was detected. Gold was also tested in the immobilized system and 90% of the initial metal added was recovered in a solution containing 213.0mg/l of the metal, the alginic matrix being responsible for 40% gold uptake.