甘肃省青年医生职业倾向实证研究

???? 目的 通过对青年医生职业倾向的调查研究,为医院人力资源管理提供依据。方法 以甘肃18个市州468位青年医生为样本,以职业锚理论为基础对他们职业倾向状况进行实证分析。结果 青年医生在各种职业倾向上均有一定比例,且职业倾向因个体人口学特征的不同而存在差异。结论 青年医生的职业倾向呈现多元化,并受管理环境等多种因素的影响,是变化发展的。

     

Genome analysis of amaranths: Determination of inter- and intra-species variations

Amaranths are an important group of plants and include grain, vegetable and ornamental types. Despite the economic importance of the amaranths, there is very little information available about the extent and nature of genetic diversity present in the genus Amaranthus at molecular level. We now report the randomly amplified polymorphic DNA (RAPD) profiles of different species of Amaranthus as well as different accessions of the species. These RAPD analyses have been carried out using 65 arbitrary sequence decamer primers. From the RAPD data, an UPGMA dendrogram illustrating the inter-as well as intra-species relationships has been computed. The putative hybrid origin of A.dubious from A. hybridus and A. spinosus is also ruled out by the RAPD data. The trends of species relationships amongst the amaranths determined by RAPDs is consistent with their cytogenetic and evolutionary relationships that have already been determined. NBRI Communication No:464 (N.S.).     

Phosphoglycerate kinase and fructose bisphosphate aldolase of Candida albicans as new antigens recognized by human salivary IgA

BackgroundCandida albicans is an opportunistic dimorphic fungus commonly present in the human oral cavity that causes infections in immunocompromised patients. The antigen variability, influenced by growth conditions, is a pathogenicity factor.AimsTo determine the effect of nutritional and heat stress on the antigen expression of C. albicans, and to identify major antigens recognized by human salivary secretory immunoglobulin A (sIgA).MethodsUnder various different nutritional conditions, heat shock was induced in C. albicans cells in stationary and exponential growth phases. The expression of protein determinants of C. albicans was assessed by Western blot analysis against human saliva. The antigens were purified and characterized by two-dimensional electrophoresis and identified by protein microsequencing.ResultsFive antigens recognized by salivary IgA were characterized as mannoproteins due to their reactivity with concanavalin A. They did not show reactivity with anti-heat shock protein monoclonal antibodies. Two of them (42 and 36 kDa) were found to be regulated by heat shock and by nutritional stress and they were identified as phosphoglycerate kinase and fructose bisphosphate aldolase, respectively.ConclusionsThese glycolytic enzymes are major antigens of C. albicans, and their differential expression and recognition by the mucosal immune response system could be involved in protection against oral infection.     

Nitrogen fixation in legumes and actinorhizal plants in natural ecosystems: values obtained using 15N natural abundance

Background: Nitrogen fixation has been quantified for a range of crop legumes and actinorhizal plants under different agricultural/agroforestry conditions, but much less is known of legume and actinorhizal plant N₂ fixation in natural ecosystems.

Aims: To assess the proportion of total plant N derived from the atmosphere via the process of N₂ fixation (%Ndfa) by actinorhizal and legume plants in natural ecosystems and their N input into these ecosystems as indicated by their ¹⁵N natural abundance.

Methods: A comprehensive collation of published values of %Ndfa for legumes and actinorhizal plants in natural ecosystems and their N input into these ecosystems as estimated by their ¹⁵N natural abundance was carried out by searching the ISI Web of Science database using relevant key words.

Results: The %Ndfa was consistently large for actinorhizal plants but very variable for legumes in natural ecosystems, and the average value for %Ndfa was substantially greater for actinorhizal plants. High soil N, in particular, but also low soil P and water content were correlated with low legume N₂ fixation. N input into ecosystems from N₂ fixation was very variable for actinorhizal and legume plants and greatly dependent on their biomass within the system.

Conclusions: Measurement of ¹⁵N natural abundance has given greater understanding of where legume and actinorhizal plant N₂ fixation is important in natural ecosystems. Across studies, the average value for %Ndfa was substantially greater for actinorhizal plants than for legumes, and the relative abilities of the two groups of plants to utilise mineral N requires further study.     

Suppression of proliferation,tumorigenicity and metastasis of lung cancer cells after their transduction by interferon-beta gene in baculovirus vector

BackgroundGene therapy represents an interesting alternative treatment for cancers. Interferon-beta is well known as a multifunctional cytokine that provides antiviral, antiproliferative, antiangiogenic and immunomodulating effects. For this reason introduction of this cytokine gene in baculovirus vector is seen as a rather promising tool for anticancer therapy.AimInvestigation of biological behavior in vitro and in vivo of lung cancer cells modified by interferon-beta gene which was introduced into the cells in vitro with baculovirus vector.Materials and MethodsStudies were performed on mouse Lewis lung carcinoma cells as the tumor model (LL cell line). Transductions of cells by recombinant baculoviruses, in vitro and in vivo analysis of tumor cell biology and immunocytochemical method have been used.ResultsThe study of various in vitro biological parameters of LL cancer cells transduced by recombinant baculovirus with interferon gene demonstrated that the transduction of cells is accompanied by significant inhibition of their proliferation and ability to form colonies in semisolid agar. Also, transduction of LL cells with interferon gene inhibited their tumorigenicity, i.e. the ability to cause formation of tumors and metastases in lungs of mice in vivo. Anti-tumor activity of recombinant interferon is realized via high level of its local production in tumors, induced by LL carcinoma cells, transduced with recombinant interferon-beta gene. Recombinant baculovirus without interferon gene did not influence significantly on tumorigenicity and metastatic ability of lung cancer cells.ConclusionsIntroduction of interferon-beta gene in Lewis lung carcinoma cells in vitro in recombinant baculovirus leads to inhibition of their proliferation potential and malignant behavior in vitro, tumorigenicity and metastatic activity in vivo.     

Colonización por Pneumocystis jirovecii en mujeres gestantes y recién nacidos en Lima,Perú

BackgroundPneumocystis jirovecii primary infection occurs asymptomatically before 6 months of age, suggesting that the infection is acquired very early in life. Furthermore, Pneumocystis pneumonia has been described in newborns, which emphasizes the importance of studying Pneumocystis colonization in mother-infant pairs.AimsTo evaluate the prevalence of Pneumocystis colonization among pregnant women and to determine the potential transplacental transmission.MethodsA cross-sectional study was carried out on HIV-negative women over 18 years-old, and 37 or more weeks of pregnancy attending Hospital Cayetano Heredia Maternity unit during 2016-2017. Clinical and demographical information was collected on them and their newborns. Oropharyngeal washes, nasal swabs, and placenta samples were collected from women, as well as a nasopharyngeal aspirate and nasal swab from newborns. All respiratory samples were analysed by nested-PCR for the detection of Pneumocystis. Placenta samples from women with a positive PCR result in their respiratory samples were also analysed by nested-PCR.ResultsOf the 92 pregnant women included, five of them (5.43%) were colonized by Pneumocystis. Pneumocystis DNA was not found in any of the 87 available newborn samples or in the placentas of the five women who had a positive result by PCR in their upper respiratory samples.ConclusionsIt was found that 5.43% of the pregnant women were colonized by Pneumocystis, there was no evidence of any role of this colonization in the transmission to their newborns, since none of them tested positive for Pneumocystis.     

Fluorescent 3-hydroxy-4-pyridinone hexadentate iron chelators: intracellular distribution and the relevance to antimycobacterial properties

Abstract  

We report the synthesis and characterization of a fluorescent iron chelator (4), shown to be effective in inhibiting the growth of Mycobacterium avium in macrophages, together with the synthesis and characterization of two unsuccessful analogues selected to facilitate identification of the molecular properties responsible for the antimicrobial activity. Partition of the chelators in liposomes was investigated and the compounds were assessed with respect to uptake by macrophages, responsiveness to iron overload/iron deprivation and intracellular distribution by flow cytometry and confocal microscopy. The synthesis of the hexadentate chelators is based on a tetrahedral structure to which three bidentate 3-hydroxy-4-pyridinone chelating units are linked via amide bonds. The structure is synthetically versatile, allowing further addition of functional groups such as fluorophores. Here, we analyse the non-functionalized hexadentate unit (3) and the corresponding rhodamine B (4) and fluorescein (5) labelled chelators. The iron(III) stability constant was determined for 3 and the values log β = 34.4 and pFe³⁺ = 29.8 indicate an affinity for iron of the same order of magnitude as that of mycobacteria siderophores. Fluorescence properties in the presence of liposomes show that 4 strongly interacts with the lipid phase, whereas 5 does not. Such different behaviour may explain their distinct intracellular localization as revealed by confocal microscopy. The flow cytometry and confocal microscopy studies indicate that 4 is readily engulfed by macrophages and targeted to cytosol and vesicles of the endolysosomal continuum, whereas 5 is differentially distributed and only partially colocalizes with 4 after prolonged incubation. Differential distribution of the compounds is likely to account for their different efficacy against mycobacteria.     

Synthesis and characterization of some metal complexes of a proton transfer salt,and their inhibition studies on carbonic anhydrase isozymes and the evaluation of the results by statistical analysis

Abstract

A novel proton transfer compound (HMeOABT)?⁺?(HDPC)^? (1) and its Fe(III), Co(II), Ni(II) and Cu(II) complexes (2–5) have been prepared and characterized by spectroscopic techniques. Complex 4 has distorted octahedral conformation revealed by single crystal X-ray diffraction method. Structures of the other complexes might be proposed as octahedral according to experimental data. All compounds were also evaluated for their in vitro inhibition effects on hCA I and II for their hydratase and esterase activities. Although there is no inhibition for hydratase activities, all compounds have inhibited the esterase activities of hCA I and II. Data have been analyzed by using a one-way analysis of variance. The comparison of the inhibition studies of 1–5 to parent compounds indicates that 1–5 have superior inhibitory effects. The inhibition effects of 2–5 are also compared to inhibitory properties of the metal complexes of MeOABT and H2DPC, revealing an improved transfection profile.     

Synthesis of 8-substituted-4-(2/4-substituted phenyl)-2H-[1,3,5]triazino[2,1-b][1,3]benzothiazole-2-thiones and their anticonvulsant,anti-nociceptive,and toxicity evaluation in mice

A number of new 8-substituted-4-(2/4-substituted phenyl)-2H-[1,3,5]triazino[2,1-b][1,3]benzothiazole-2-thiones (4a–t) were synthesized and evaluated for their anticonvulsant, anti-nociceptive, hepatotoxic, and neurotoxic properties. The titled compounds (4a–t) were obtained by cyclization of N-{[6-substituted-1,3-benzothiazol-2-yl)amino]carbonothioyl}-2/4-substituted benzamides (3a–t) by refluxing in n-butanol. All the newly synthesized compounds were screened for their anticonvulsant activity in a mouse seizure model and were compared with the standard drug phenytoin. Compounds 4a, 4c, 4f, and 4l showed complete protection after time periods of 0.5?h and 4?h. Some of the selected compounds were evaluated for their neurotoxic and hepatotoxic effects, and none of these showed any sign of neurotoxicity or hepatotoxicity. Compounds 4a–t were also evaluated for their anti-nociceptive activity by a thermal stimulus technique using diclofenac as standard. Compounds 4o, 4q, and 4t displayed highly potent analgesic activity with p?<?0.01.     

Biochemical properties of new synthetic carnosine analogues containing the residue of 2,3-diaminopropionic acid: the effect of N-acetylation

Summary. Three novel carnosine analogues 7–9 containing the residue of L(+)2,3-diaminopropionic acid with different degree of N-acetylation instead of -alanine have been synthesized and characterized. Comparative analysis of hydrolysis by carnosinase revealed that the mono- and bis-acetylated compounds 8 and 9 are resistant to enzymatic hydrolysis and act as competitive inhibitors of this enzyme. The hydroxyl radical scavenging potential of the three analogues was evaluated by their ability to inhibit iron/H₂O₂-induced degradation of deoxyribose. The second-order rate constants of the reaction of compounds 7–9 with hydroxyl radical were almost identical to that of carnosine. These compounds were also found to act as protective agents against peroxynitrite-dependent damage as assessed by their ability to prevent nitration of free tyrosine induced by this species.     

Phytoclimatic segregation of sub-Antarctic Nothofagus woodland types in Tierra del Fuego,southern South America

Background: Climatic variables determining the most suitable sites for the woodlands of Tierra del Fuego are not yet as well understood as those related to their geographical range.

Aim: The aim of this paper is to provide some insights into the relationships between climatic niche and current distribution of three Nothofagus species in Tierra del Fuego.

Methods: We have identified the climatic variables responsible for the most suitable sites for three sub-Antarctic Nothofagus woodland types within their climatic ranges by calculating suitability indices, using the CLIMPAIR niche-based phytoclimatic model.

Results: The distribution range of the major Nothofagus woodlands is mainly driven by variables related to water stress, whereas phytoclimatic suitability is mainly driven by thermal variables related to warm summer temperatures for Nothofagus betuloides and N. pumilio and to winter cold for N. antarctica that are also mainly responsible for the peculiarity of the Fueguian climate.

Conclusions: These findings introduce a new perspective in the study of the Nothofagus ecology, based on the climatic traits responsible for the high-suitability locations instead of the traditional focus on the overall geographical distribution.     

Cholinesterase inhibitory triterpenoids from the bark of Garcinia hombroniana

Abstract

Context: Garcinia hombroniana Pierre, known as manggis hutan in Malaysia is a rich source of xanthones and benzophenones.

Objectives: This study was aimed to isolate and characterize potential cholinesterase inhibitors from the extracts of G. hombroniana bark and investigate their interactions with the enzymes.

Materials and methods: The dichloromethane extract afforded five triterpenoids which were characterized by NMR and mass spectral techniques. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds were also tested for their antioxidant capacity.

Results: The isolated triterpenoids were identified as: 2β-hydroxy-3α-O-caffeoyltaraxar-14-en-28-oic acid (1), taraxerol (2), taraxerone (3), betulin (4) and betulinic acid (5). Compound 1 was the most active dual inhibitor of both AChE and BChE. Compound 1 also showed good antioxidant activities.

Conclusion: Compound 1 had dual and moderate inhibitory activity on AChE and BChE worthy for further investigations.     

New N,N-dimethylcarbamate inhibitors of acetylcholinesterase: design synthesis and biological evaluation

Abstract

A series of N,N-dimethylcarbamates containing a N,N-dibenzylamino moiety was synthesized and tested to evaluate their ability to inhibit Acetylcholinesterase (AChE). The most active compounds 4 and 8, showed 85 and 69% of inhibition at 50?μM, respectively. Furthermore, some basic SAR rules were outlined: an alkyl linker of six methylene units is the best spacer between the carbamoyl and dibenzylamino moieties; electron-withdrawal substituents on aromatics rings of the dibenzylamino group reduce the inhibitory power. Compound 4 produces a slow onset inhibition of AChE and this is not due to the carbamoylation of the enzyme, as demonstrated by the time-dependent inhibition assay of AChE with compound 4 and by MALDI-TOF MS analysis of trypsinized AChE inhibited by compound 4. Instead, compound 4 could act as a slow-binding inhibitor of AChE, probably because of its high conformational freedom due to the linear alkyl chain.     

Familial Accumulation of Social Anxiety Symptoms and Maladaptive Emotion Regulation

BackgroundSocial anxiety is thought to be strongly related to maladaptive emotion regulation (ER). As social anxiety symptoms accumulate in families, we hypothesize that maladaptive ER is also more prevalent in families with anxious children. Thus, we analyze differences in emotion regulation of both child and mother in relation to social anxiety, as well as both their ER strategies in dealing with anxiety. Further, a positive relation between child and maternal ER strategies is assumed.MethodChildren (aged 9 to 13 years) with social, anxiety disorder (SAD; n = 25) and healthy controls (HC, n = 26) as well as their mothers completed several measures of social anxiety and trait ER strategies towards anxiety. As ER of children is still in development, age is considered as covariate.ResultsSAD children and their mothers reported more maladaptive ER strategies than HC dyads. Maternal maladaptive ER was related negatively to child adaptive ER which was further moderated by the child’s age.DiscussionMaladaptive ER strategies seem to contribute to the exacerbation of social anxiety in both mother and child. Mothers reporting maladaptive ER may have difficulties supporting their child in coping with social anxiety while simultaneously also experiencing heightened levels of anxiety. Deeper understanding of interactional processes between mothers and children during development can assist the comprehension of factors maintaining SAD. Implications for future research and possible consequences for interventions are discussed.     

Finding your mate in a seabird colony: contrasting strategies of the Guillemot Uria aalge and King Penguin Aptenodytes patagonicus

Capsule King Penguins recognize their mates by voice, but Guillemots do not need acoustic cues even though their calls show individual variation.

Aims To determine whether the structure of Guillemot calls could allow individual recognition, as with King Penguin, and whether acoustic cues are used to locate mates among a dense mass of conspecifics at a colony.

Methods Observations were made on breeding Guillemots and King Penguins. Calls made by birds returning to their mates were recorded, the signals digitized and the calls analysed. Calls were later played back to the mates of the birds concerned and the effects noted on both them and their neighbours.

Results Both Guillemots and King Penguins emitted calls on return to the breeding site which contained individual signatures and were therefore potentially usable for mate recognition. In King Penguins, auditory recognition was essential for finding a mate, whereas in Guillemots most of the arriving birds located their mate in a dense crowd of conspecifics without the help of acoustic signals. Guillemots could differentiate neighbours from strangers without auditory cues.

Conclusion Calls are essential for the successful identification of mates by King Penguins but not by Guillemots.     

Hybrid α/β-peptides: For-Met-Leu-Phe-OMe analogues containing geminally disubstituted β2,2- and β3,3-amino acids at the central position

Summary. The two fMLF-OMe analogues For-Met-β³hAc₆c-Phe-OMe (6) and For-Met-β²hAc₆c-Phe-OMe (12) and their corresponding N-Boc derivatives 5 and 11 have been synthesized and their biological activity towards human neutrophils evaluated. The N-formyl peptides 6 and 12 exhibit good activity as chemoattractans and 12 is highly active in superoxide anion production. The preferred solution conformation of the two N-formyl derivatives has been discussed.     

Design,green synthesis and pharmacological evaluation of novel 5,6-diaryl-1,2,4-triazines bearing 3-morpholinoethylamine moiety as potential antithrombotic agents*

The aim of this research work was to investigate a series of novel 5,6-diaryl-1,2,4-triazines (3a–3q) containing 3-morpholinoethylamine side chain, and to address their antiplatelet activity by in vitro, ex vivo and in vivo methods. All compounds were synthesized by environment benign route and their structures were unambiguously confirmed by spectral data. Compounds (3l) and (3m) were confirmed by their single crystal X-ray structures. Out of all the synthesized compounds, 10 were found to be more potent in vitro than aspirin; six of them were found to be prominent in ex vivo assays and one compound (3d) was found to have the most promising antithrombotic profile in vivo. Moreover, compound (3d) demonstrated less ulcerogenicity in rats as compared to aspirin. The selectivity of the most promising compound (3d) for COX-1 and COX-2 enzymes was determined with the help of molecular docking studies and the results were correlated with the biological activity.     

Cross sectional study of reporting of epileptic seizures to general practitioners

ObjectiveComparison of reporting of recent epileptic seizures by patients to a doctor and anonymously.DesignCross sectional study of patients with epilepsy by comparison of paired questionnaires.SettingRural and urban general practices in Norfolk. Participants122 patients aged over 16 years and able to self complete a questionnaire who were recruited by 31 general practitioners when attending for review of their epilepsy.Results18 patients failed to report a seizure in the past year to their general practitioner (uncontrolled epilepsy). 40% (24/60) of people with epilepsy who anonymously reported a seizure in the past year held a driving licence, but only six revealed this to their general practitioner. The unemployment rate was 34%, substantially higher than the 9% in the general population. Measures of anxiety, depression, and stigmatisation were higher in patients with uncontrolled epilepsy.ConclusionsA significant proportion of patients with epilepsy underreport their seizures. Recognition of underreporting is important if patients are to benefit from adequate and appropriate treatment. General practitioners'' ability to treat epilepsy is hampered by their role in regulating the rights of epileptic patients to hold a driving licence or access certain occupations.

Key messages

• People with epilepsy may be reluctant to report seizures to their general practitioners as epilepsy affects their eligibility for a driving licence and access to various employment and leisure activities
• In this study about a sixth of patients anonymously reported seizures in the past year which they had not revealed to their general practitioner
• 40% of patients who anonymously reported a seizure in the past year held a driving licence, but only a quarter of these admitted this to their general practitioner
• People who had had seizures in the past year were significantly more depressed and felt more stigmatised than those who had not had a seizure
• Underreporting of seizures has important consequences for treatment, and doctors need to put more effort into explaining this to patients