医学院校学生染发现状的调查

指出了在医学生中有较大部分学生染发,尤其是女生的染发率较高,大部分医学生都是为了美而染发,而且大部分学生对染发剂的了解程度都很低,并不清楚染发对人体健康的危害,对医学院学生的染发现状的进行了调查与讨论,提出了应加强对医学生宣传染发对人体健康的危害,提高自我保护意识。以期提供参考。

Gel Filtration Chromatography Combined with Bradford Method for Determination of Total Residual Protein in Ferment Antibiotics

Aim A novel method has been developed for evaluation of the levels of total residual protein in antibiotics produced by fermentation using gel filtration chromatography (GFC) combined with Bradford assay based on determination of residual protein in lincomycin hydrochloride. Methods The chromatographic conditions were SuperdexTM peptide column, 0.01 mol*L-1 phosphate buffer solution as mobile phase, and flow rate of 1 mL·min-1. Five hundred microliters of lincomycin hydrochloride solution (3 g of lincomycin hydrochloride dissolved in 10 mL of mobile phase) was injected into the chromatograph and the eluted solution was collected between 6 min and 14.5 min (protein eluted from column within this period), and the residual content of total protein in the eluted solution was assayed using Bradford assay method. Results The average recovery was more than 90% for bovine serum albumin, the calibration equation for the range of 0-12 μg·mL-1 of protein was y=-0.002 4x2+0.064 2x+0.002 9, r2=0.999 9, RSD=0.1%-0.9%, and the LOD and LOQ were 3 and 10 ng·mL-1 of protein, respectively. Conclusion The novel method for determining the residual protein in ferment antibio-tics is simple, rapid, and precise.

Epidemiology of hepatitis C virus infection

Globally, hepatitis C virus (HCV) has infected an estimated 130 million people, most of whom are chronically infected. HCV-infected people serve as a reservoir for transmission to others and are at risk for developing chronic liver disease, cirrhosis, and primary hepatocellular carcinoma (HCC). It has been estimated that HCV accounts for 27% of cirrhosis and 25% of HCC worldwide. HCV infection has likely been endemic in many populations for centuries. However, the wave of increased HCV-related morbidity and mortality that we are now facing is the result of an unprecedented increase in the spread of HCV during the 20th century. Two 20th century events appear to be responsible for this increase; the widespread availability of injectable therapies and the illicit use of injectable drugs.

Severe acute pancreatitis: Pathogenetic aspects and prognostic factors

Approximately 20% of patients with acute pancreatitis develop a severe disease associated with complications and high risk of mortality. The purpose of this study is to review pathogenesis and prognostic factors of severe acute pancreatitis （SAP）. An extensive medline search was undertaken with focusing on pathogenesis, complications and prognostic evaluation of SAP. Cytokines and other inflammatory markers play a major role in the pathogenesis and course of SAP and can be used as prognostic markers in its early phase. Other markers such as simple prognostic scores have been found to be as e^ective as multifactorial scoring systems （MFSS） at 48 h with the advantage of simplicity, efficacy, low cost, accuracy and early prediction of SAP. Recently, several laboratory markers including hematocrit, blood urea nitrogen （BUN）, creatinine, matrix metalloproteinase-9 （MMP-9） and serum amyloid A （SAA） have been used as early predictors of severity within the first 24 h. The last few years have witnessed a tremendous progress in understanding the pathogenesis and predicting the outcome of SAP. In this review we classified the prognostic markers into predictors of severity, pancreatic necrosis （PN）, infected PN （IPN） and mortality.

Germination Tolerance of Four Mutant Lines of Barley （Hordium vulgare L.）, Wheat （Triticum aestivum L.） and Garden Cress （Lipidium sativum L.） to Crude Oil Contaminated Soil

Phytoremediation shows promise as an alternative low-cost to most remediation methods. This study evaluated the germination of six crops, including four mutant lines of barley （Hordium vulgate L.） （1-9-3, 150-2-3, 1-1-200 and 150-1-5）, wheat （Triticum aestivum L.） and garden cress （Lipidium sativum L.）. This experiment was conducted in laboratory at room temperature. Oil extracted from crude oil contaminated soil was added to sand used in different concentrations （0%, 2%, 4%, 6%, 8% and 10%）. 10 seeds of each crop were sown in ptri-dishes with different treatments separately. For Each treatment four replicates were used in completely randomized design, germination percent was calculated, after one week, shoot and root length were measured. Data were statistically analyzed using MINTAB version 12. The results show that barley mutant line （150-2-3） was significantly different from other entries in germination percent, shoot and root length except mutant line 150-1-5 in germination percent. Results demonstrated that the mutant line 150-2-3 was promising to remediate crude oil contaminated soil.

OCCURRENCE OF THE LUNG FLUKE, PARAGONIMUS HETEROTREMUS IN MANIPUR, INDIA

Objectives.To determine the natural crustacean host,the Paragonimus species,and to investigate the potential host-parasite relationship between Manipur Paragonimus and some of the laboratory animals.Methods. The laboratory animals such as puppies,albino rats and Swiss mice were infected orally with metacercariae isolated from the fresh water crabs,Potamiscus manipurensis. The fecal specimens of the experimentally infected animals were examined microscopically for Paragonimus eggs at regular intervals. The animals were autopsied on days 35～328 after infection and the isolated worms were flattened between glass slides and fixed in 70% alcohol. The worms were stained with carmine and mounted with Canada balsam for morphological studies. The eggs were collected in 5% formol saline solution for microscopy. The flukes were classified into 4 developmental stages.Results. A total of 11 worms,5 mature,5 immature and 1 pre-adult were recovered. The morphological features of the metacercariae,worms and eggs were similar to those of Paragonimus heterotremus.Conclusion. Manipur is one of the rare areas in the world where Paragonimus heterotremus is prevalent and the puppies are ideal experimental animal host. This species may be one of the important causes of paragonimiasis in animals and humans in Manipur.

Choroidal Tuberculoma in an Immunocompetent Young Patient

TUBERCULOSIS （TB） remains one of the leading causes of preventable morbidity and mortality from infectious disease worldwide.1 It is a chronic progressive granulomatous infection caused by Mycobacterium tuberculosis （M. tuberculosis）.

Global and Regional Trends and Projections of Infective Endocarditis-Associated Disease Burden and Attributable Risk Factors from 1990 to 2030

Objective To forecast the future burden and its attributable risk factors of infective endocarditis(IE).Methods We analyzed the disease burden of IE and its risk factors from 1990 to 2019 using the Global Burden of Disease 2019 database and projected the disease burden from 2020 to 2030 using a Bayesian age-period-cohort model.Results By 2030,the incidence of IE will increase uncontrollably on a global scale,with developed countries having the largest number of cases and developing countries experiencing the fastest growth.The affected population will be predominantly males,but the gender gap will narrow.The elderly in high-income countries will bear the greatest burden,with a gradual shift to middle-income countries.The incidence of IE in countries with middle/high-middle social-demographic indicators(SDI) will surpass that of high SDI countries.In China,the incidence rate and the number of IE will reach 18.07 per 100,000 and 451,596 in 2030,respectively.IEassociated deaths and heart failure will continue to impose a significant burden on society,the burden on women will increase and surpass that on men,and the elderly in high-SDI countries will bear the heaviest burden.High systolic blood pressure has become the primary risk factor for IE-related death.Conclusions This study provides comprehensive analyses of the disease burden and risk factors of IE worldwide over the next decade.The IE-associated incidence will increase in the future and the death and heart failure burden will not be appropriately controlled.Gender,age,regional,and country heterogeneity should be taken seriously to facilitate in making effective strategies for lowering the IE disease burden.

Prevalence and Pathology of Fasciola Species in Slaughtered Cattle

Studies on the prevalence and pathology of Fasciola specie were carried out in nine abattoirs in Ilorin, capital city of Kwara State, Nigeria. The research was conducted during the period August, 2006 - May, 2007. Of the 63,649 cattles examined at the various abattoirs which are lpata, Sango, Oloje, Baboko, Oke-oyi, Iporin, Panada, Oke-ose and Marafa, 1,434 representing 25.2% were infected with Fasciola species while 114 representing 6.5% were condemned. Iporin slaughter slab had the highest prevalence of 3.6%, followed by panada with 3.4% and Ipata having the least prevalence of 1.6%. Similarly analysis of data on monthly basis showed that March had the highest prevalence of 2.8%, followed by April with 2.6% and December with the least prevalence of 1.8%. Overall infestation was 22.7% while overall condemnation was 6.5%. There was a significant difference （X^2 = 23.7, P 〈 0.05） in the monthly infestation rate. Also, there was no significant difference （X^2 = 10.7, P 〉 0.05） between the infection rate and condemnation among the various abattoirs. The factors responsible for the prevalence of Fasciola specie and pathology of infection are highlighted.

Correlated Color Temperature Tunable Multi-chip Light Emitting Diodes Light Source Design

One of the methods to derive white light from light emitting diodes(LEDs)is the multi-chip white LED technology,which mixes the light from red,green and blue LEDs.Introduced is an optimal algorithm for the spectrum design of the multi-chip white LEDs in this paper.It optimizes the selection of single color LEDs and drive current controlling,so that the multi-chip white LED achieves the target correlated color temperature(CCT),as well as high luminous efficacy and good color rendering.A CCT tunable LED light source with four high-power LEDs is realized based on the above optimal design.Test results show that it maintains satisfactory color rendering and stable luminous efficacy across the whole CCT tuning range.Finally,discussed are the design improvement and the prospect of the future applications of the CCT tunable LED light source.

Prevalence,genotypes and factors associated with HCV infection among prisoners in Northeastern Brazil

AIM： To determine hepatitis C virus （HCV） seropreva- lence and its genotypes, and to identify the factors associated with HCV infection. METHODS： This cross-sectional study, conducted in two prisons （one male and one female） in the State of Ser- gipe, Brazil, comprised 422 subjects. All of the prisoners underwent a rapid test for the detection of HCV antibod- ies. Patient~ with a positive result were tested for anti- HCV by enzyme linked immunosorbent assay and for HCV RNA by qualitative polymerase chain reaction （PCR）. The virus genotype was defined in every serum sample that presented positive for PCR-HCV. In order to determine the factors independently associated with positive serol- ogy for HCV, multivariate logistic regression was used. RESULTS： HCV seroprevalence was 3.1%. Of the 13 subjects with positive anti-HCV, 11 had viremia confirmed by PCR. Of these, 90.9% had genotype 1. A total of 43 （10.2%） were injecting drug users, and HCV seroprevalence in this subgroup was 20.6%. The variable most strongly associated with positive serology for HCV was use of injecting drugs [odds ratio （OR）, 23.3; 95% confidence interval （CI）, 6.0-90.8]. Age over 30 years （OR, 5.5; 95%CI, 1.1-29.2）, history of syphilis （OR, 9.8; 95%CI, 1.7-55.2） and history of household contact with HCV positive individual （OR, 14.1; 95%CI, 2.3-85.4） were also independently associated with HCV infection. CONCLUSION： Most of the HCV transmissions result from parenteral exposure. However, there is evidence to suggest a role for sex and household contact with an infected subject in virus transmission.

Efficacy and safety of fidaxomicin versus vancomycin for Clostridium difficile infection: systematic review and meta-analysis

To compare the efficacy and safety of fidaxomicin and vancomycin for the treatment of patients with Clostridium difficile infection （CD1）, randomized controlled trials （RCTs） of fidaxomicin versus vancomycin for the treatment of CDI published in Pubmed, Embase, Web of Science and the Cochrane library were searched. Two reviewers independently extracted the data. The primary outcome was the rates of clinical cure. The secondary endpoints were the rates of CDI recurrence in the 4 weeks period after the end of therapy and rates of global cure, adverse events. Meta-analysis was performed using the Mantle-Haenszel fixed effect method （FEM）. Odds ratios （ORs） with 95% confidence intervals （95% CIs） were reported. The results indicated that two large randomized controlled trials were included in the meta-analysis. Clinical cure with fidaxomicin was similar to with vancomycin both in the modified intention to treat （OR = 1.17, 95% CI 0.82-1.66, P = 0.40） and in the per-protocol population （OR = 1.24, 95% CI 0.80-1.92, P = 0.34）. There were no significant differences in the rates of clinical cure between fidaxomicin and vancomycin in the subgroups analyzed by age, patients＇ status, and previous CDI, infection with B 1 strain, severity baseline, and exposure to concomitant antibiotics. Recurrence of CDI was significantly less common among fidaxomicin-treated patients compared with vancomycin-treated patients both in the modified intention-to-treat population （OR = 0.47, 95% CI 0.34-0.65, P〈0.00001） and in the per-protocol population （OR = 0.45, 95% CI 0.31-0.62, P〈0.0001）. Treatment with fidaxomicin compared with vancomycin was associated with significantly higher rates of global cure both in the modifed intention-to-treat population （OR = 1.75, 95% CI 1.35-2.27, P〈0.0001） and in the per-protocol population （OR = 1.86, 95% CI 1.40-2.47, P〈0.0001）. Our recta-analysis suggests that fidaxomicin is not superior to vancomycin in rates of clinical cure, while fidaxomicin significantly decreases the rates of CDI recurrence and significantly improves the rates of global cure compared with vancomycin. Thus, fidaxomicin is a promising candidate for treatment of the CDI, especially in decreasing the rates of CDI recurrence and improving the rates of global cure.

A review in emergency central venous catheterization

Central venous catheterization is widely used in the emergency setting. This review aims to assess central venous catheterization from the perspectives of types of catheters, sites of insertion, and tech- niques. In emergency conditions, non-tunneled catheters are preferred because the technique for its insertion is not complicated and less time-consuming. The size of catheter depends on the purpose of catheterization. For example, a large bore catheter is needed for rapid infusion. The ideal catheterization site should bear fewer thromboses, lower infectious rate, and fewer mechanical complications. Thus the femoral vein should be avoided due to a high rate of colonization and thrombosis while the subclavian vein seems to exhibit fewer infectious complications compared with other sites. The ultrasound-guided technique increases the success rate of insertion while decreases the mechanical complications rate,

Hydrophobe-substituted bPEI derivatives: boosting transfection on primary vascular cells

Gene therapy targeted to vascular cells repre- sents a promising approach for prevention and treatment of pathological conditions such as intimal hyperplasia, in-stent and post-angioplasty restenosis. In this context, polymeric non-viral gene delivery systems are a safe alternative to viral vectors but a further improvement in efficiency and cytocom- patibility is needed to improve their clinical success. Herein, a library of 24 branched polyethylenimine （bPEI） derivatives modified with hydrophobic moieties was synthesised, char- acterised and tested in vitro on primary vascular cells, aim- ing to identify delivery agents with superior transfection effi- ciency and low cytotoxicity. Low molecular weight PEIs （0.6, 1.2 and 2 kDa） were grafted with long （C18） and short （C3） aliphatic chains, featuring different unsaturation degrees and degrees of substitution. 0.6 kDa bPEI-based derivatives were generally ineffective in transfection on vascular smooth mus- cle cells （VSMCs）, while among the other derivatives some promising vectors were identified. Forcing polyplexes on the cell surface by means of centrifugation invariably boosted transfection levels but increased cytotoxicity as well. Of note, a propionyl-snbstituted derivative （PEI2-PrA1, C3：0） was the most effective on both VSMCs and endothelial cells （ECs）, with higher and more sustained gene expression in combi- nation with markedly lower cytotoxicity with respect to the gold standard 25 kDa bPEI. In addition, a linoleoyl-substi- tuted derivative （PEI1.2-LA6, C18：2） owing to its high effi- ciency in VSMCs and relative inefficacy in ECs, combined with tolerable cytotoxicity was proposed as a vector for spe- cific VSMCs targeting.

A note on an age-of-infection SVIR model with nonlinear incidence

In this paper, nonlinear incidence rate is incorporated into an age-of-infection SVIR epidemiological model. By the method of Lyapunov functionals, it is shown that the basic reproduction number R0 of the model is a threshold parameter in the sense that if R0 〈 1, the disease dies out, while if R0〉1, the disease persists.

Stability analysis for delayed viral infection model with multitarget cells and general incidence rate

In this paper, the sharp threshold properties of a （2n ＋ 1）-dimensional delayed viral infection model are investigated. This model combines with n classes of uninfected tar- get cells, n classes of infected cells and nonlinear incidence rate h（x,v）. Two kinds of distributed time delays are incorporated into the model to describe the time needed for infection of uninfected target cells and virus replication. Under certain conditions, it is shown that the basic reproduction number is a threshold parameter for the existence of the equilibria, uniform persistence, as well as for global stability of the equilibria of the model.