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Micro-defects inside metal matrix composite structure seriously influence the mechanic properties of materials and can undermine machine operations. In order to detect the micro-defects, we can make use of one of the nonlinear acoustic features, i.e., harmonics, which usually appear together with ultrasound when propagating through a damaged material. Based on the relationship between the harmonics, a method of using nonlinear acoustic harmonic amplitude ratio to distinguish micro-defects in metal matrix composite structure is discussed. The test results show that acoustic features, such as second harmonic excitation efficiency were very obvious for the damaged group samples. The method presented is effective in detecting the micro-defects, which means that nonlinear acoustic waves may provide us a good solution for quantitative evaluation of the early damages in metal matrix composite structure.

A novel Mo–Si–B double-layer coating was prepared for the carbon/carbon (C/C) composites by pack cementation in an argon atmosphere. The structures of the double-layer coatings were characterized by XRD and SEM. The as-received coating shows an excellent oxidation resistance at high and intermediate temperature. It could effectively protect C/C composites from oxidation for 30 h with a weight loss of 0.9% in air at 1873 K, and for 25 h with a weight loss of l.7% at 1173 K. The oxidation protective coating was principally due to producing eutectic glass film for decreasing oxygen diffusing through the penetrable cracks in the coating.

A dinuclear copper(II) complex [Cu2(oxheel)] was synthesized and its structure was analyzed. This compound was then mixed with a surfactant (Brij35 or LSS) to form a metallomicelle, which would catalyze the phenol oxidation with the hydrogen peroxide (H2O2). The reaction mechanism and the mathematic model for the kinetics of this reaction were proposed, and the effect of the molar ratio between H2O2 and catalyst, of the temperature and of the pH levels on the rate of catalytic reaction were studied.

In order to effectively employ the unique high temperature mechanical properties of carbon/carbon composite substrates, SiC coatings reinforced by SiC whiskers were prepared by pack cementation method. The effect of SiC whiskers on the oxidation resistance properties of the single-layer coating and double-layer coating was investigated. SiC whiskers in the single-layer SiC coating have little effect on the anti-oxidation property but obviously improve the thermal shock property. The double-layer coating with inner-layer reinforced coating exhibits more perfect anti-oxidation ability than the double-layer coating with SiC inner-layer coating.

BACKGROUND: To identify the genetic risk of six genetic variants at 8q21 and 8q24 (including rs1512268, A; rs12543663, C; rs10086908, C; rs1016343, T; rs13252298, A, and rs6983561, C) associated with prostate cancer in Beijing and Tianjin (Jing-jin) area residents in northern China. METHODS: 574 subjects were enrolled. Blood samples and clinical information were collected from histologically confirmed prostate cancer cases (n = 286) and clinically evaluated matched normal controls (n = 288) from Chinese men in northern China. Six SNPs at 8q21 and 8q24 were genotyped by high-resolution melt and sequencing in subjects. We compared statistical differences between the prevalence of risk genotypes with prostate cancer in cases and controls and analyzed the association between clinical covariates and risk loci in case groups to infer their relationship with aggressive prostate cancer. RESULTS: Three genotypes of rs10086908, CC (OR = 2.48; 95% CI = 1.02 - 5.98, p = 0.037) rs1016343, TT (OR = 1.64, 95% CI = 1.07 - 2.53, p = 0.023); and rs6983561, CC (OR = 1.91; 95% CI = 1.09 - 3.63, p = 0.044) at 8q24 were identified to be associated with prostate cancer risk in Jing-jin Chinese. The D' values of both two-locus haplotypes (T-A: rs1016343 vs. rs13252298; T-C: rs1016343 vs. rs6983561) were 0.907 and 0.859, respectively, the three-locus haplotype, only TAC constituted by the loci (rs1016343, T; rs13252298, A; rs6983561, C) was also associated with prostate cancer (p = 0.033), revealing rs1016343 vs. rs6983561 with significant differences between cases and controls. According to clinical covariates and odds ratios of risk genotypes relative to non-risk genotypes, rs6983561, CC was associated with age (OR = 2.5; 95% CI = 1.02 - 6.13, p = 0.039), and tumor aggressiveness (OR = 1.15; 95% Cl = 1.06 - 1.23, p = 0.013). CONCLUSIONS: The loci including rs10086908, rs1016343, and rs6983561 at 8q24 could be associated with prostate cancer in Jing-jin residents in northern China. Our results suggest that these loci could influence susceptibility to prostate cancer in the northern Chinese population.

To explore the association of the androgenic receptor (AR) CAG repeats with the risks of benign prostatic hyperplasia (BPH) and prostate cancer (PCa).We searched the major databases at home and abroad for the literature addressing the correlation of the AR gene CAG repeats with BPH and PCa. Based on the results of heterogeneity tests, we used the M-H fixed effect model and random effect model to pool the odds ratio (OR) effect size. We evaluated publication bias by Begg and Egger bias analysis, investigated the association of CAG repeats with the risks of BPH and PCa by systematic review, and stratified their relationship according to the races of the patients.Based on the selection criteria, 4 of the 29 identified studies were included, with 485 cases of BPH, 767 cases of PCa, and 709 controls. There was no heterogeneity between the BPH and control groups, and no correlation between short CAG repeats and BPH after pooling the odds ratio (OR) effect size. Heterogeneity was found among the BPH, PCa and control groups. Random effects model suggested an association of short CAG repeats with the risk of PCa (OR(PCa/control) = 1.45, OR(PCa/BPH) = 1.86, OR(PCa/(BPH + control)) = 1.66), while subgroup analysis with racial stratification indicated inter-ethnic differences between the two. Begg and Egger bias analysis showed no significant publication bias.Shorter CAG repeats are positively correlated with the risk of PCa but not with that of BPH.

How clusters is aggregated have great effect on the function and dynamic of complex network. A percolation transition model is introduced in this paper which can be described with the clusters aggregated probability p(Ci)~1-Ci / (Cmax + α), where Ci is the size of the cluster, Cmax is the size of the largest cluster and α is disturbance parameter. This model respectively introduce weakly and strongly discontinuous percolation transition underlying the different α and reveal the strongly impact of clusters' aggregated probability.

To explore the association between the common variations of TET2 (rs7679673, A), MTK2 (rs6465657, T) and FAM84B (rs12543663, C) genes and prostate cancer (Pca) risk in Chinese population in Beijing, and to understand the relationship between genotypes and phenotypes including clinical characteristics and life style, etc. in patients with prostate cancer.Based on a case-control study, 124 patients with prostate cancer and 138 age-matched control subjects were recruited. Information of clinical phenotype and life style, etc. in the prostate cancer patients was collected. We compared the differences of allele and genotype frequencies of TET2 (rs7679673, A), LMTK2 (rs6465657, T) and FAM84B (rs12543663, C) gene expressions between the two groups for the allele and genotype frequencies, and explored the relationship between different genotypes and clinical features such as patient age, BMI, Gleason score, PSA level and tumor stage, by Chi-square test in patients with PCa. Multifactor dimensionality reduction was used to detect the gene-gene interactions.The FAM84B (rs12543663, C) C carriers frequency had significant difference between the case group and the control group (χ(2) = 3.980 P = 0.046; OR = 1.883; 95%CI = 1.006-3.526). The allele and genotype frequencies of TET2 gene (rs7679673, A) and LMTK2 gene (rs6465657, T) were not significantly different between the case group and the control group (P0.05). Analysis of the genotypes and clinical phenotypes showed that the genetic type of FAM84B C carriers [CX (CC + CA)] were significantly associated with cancer stage (χ(2) = 9.585; P = 0.002; OR = 3.740; 95%CI = 1.580 - 8.853). Association between three loci and 12 kind of relevant outcomes was found in TET2 A carriers and the smoking and drinking patients (all P0.05). Significant correlation was also found between LMTK2 (rs6465657, T) TX carriers and surgery (χ(2) = 8.612; P = 0.003; OR = 0.174; 95%CI 0.049 - 0.620). No significant correlation was seen with other covariates (P0.05). Dendrogram analysis among the three loci showed that the best model consisted of the three sites (P = 0.0270), cross validation consistency: 10/10, and testing balanced accuracy: 0.5120. There may be gene-gene interaction among TET2 (rs7679673, A), LMTK2 (rs6465657, T), and FAM84B (rs12543663, C).There may be obvious association of FAM84B (rs12543663, C) gene with prostate cancer risk and the stages, and the synergistic effects of TET2 (rs7679673, A), LMTK2 (rs6465657, T) and FAM84B (rs12543663, C) genes may have an association with prostate cancer risk in Chinese population.

Background The abnormality of interleukin-21 (IL-21)-IL-21-receptor (IL-21R) system has been found in many autoimmune diseases including autoimmune thyroid diseases (AITDs). In this study, we investigated whether polymorphisms of the IL-21 and IL-21R are associated with Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), two major forms of AITDs, among a Chinese population. Methods Rs907715, rs4833837, rs2221903 and rs2055979 of the IL-21 gene and rs3093301 and rs2285452 of the IL-21R gene were explored in a case–control study including 405 GD, 228 HT patients and 242 controls. These genes were genotyped by the PCR and restriction fragment length polymorphism (RFLP) analysis and the MASS spectrometry method. Results For IL-21 gene, we identified and confirmed a higher prevalence of A alleles of rs2221903 (P = 0.018, OR = 1.50 95% CI = 1.07-2.09) in GD patients. We also found a significant association between rs2221903 and HT (allele: P = 0.009, OR = 1.69 95% CI = 1.13-2.51; genotype: recessive P = 0.021, OR = 11.72 95% CI = 1.46-94.13). For the IL-21R gene, compared with controls, the genotype frequencies of rs3093301 and rs2285452 were significantly different in HT patients using dominant genetic model (P = 0.023, OR = 1.61 95% CI = 1.07-2.42; P = 0.031, OR = 1.71 95% CI = 1.05-2.80, respectively). Furthermore, the haplotype AA containing the major alleles of rs4833837 and rs2221903 was associated with increased susceptibility to GD with an OR of 1.50(95% CI =1.08-2.09, P = 0.016), and to HT with an OR of 1.69(95% CI =1.14-2.52, P = 0.009). Conclusion Our results indicated that the SNPs of the IL-21 gene is associated with the development of GD. In addition, we found that individuals with the SNPs of the common IL-21 and IL-21R may have higher risk of HT.

It is known that heat transfer between two liquid-reservoirs maintained at different temperatures and connected to each other by a capillary bundle is markedly enhanced by oscillatory flow in the bundle. In this paper, first, the effects of physical properties of the working liquid on the enhanced heat flow rate are investigated. Second, the optimum operating condition maximizing the ratio of the enhanced heat flow rate to power input is examined. Finally, to increase further the ratio, a novel type with a phase shift between oscillatory flows in adjacent tubes is proposed.

AIM: To explore Chinese physicians’ perceptions towards fecal microbiota transplantation (FMT) and to provide information and an assessment of FMT development in China. METHODS: A self-administered questionnaire was developed according to the FMT practice guidelines and was distributed to physicians in hospitals via Internet Research Electronic Data Capture (REDcap) software and electronic mails to assess their attitudes toward and knowledge of FMT. The questionnaire included a brief introduction of FMT that was followed by 20 questions. The participants were required to respond voluntarily, under the condition of anonymity and without compensation. Except for the fill-in-the-blank questions, all of the other questions were required in the REDcap data collection systems, and the emailed questionnaires were completed based on eligibility. RESULTS: Up to December 9, 2014, 844 eligible questionnaires were received out of the 980 distributed questionnaires, with a response rate of 86.1%. Among the participants, 87.3% were from tertiary hospitals, and there were 647 (76.7%) gastroenterologists and 197 (23.3%) physicians in other departments (non-gastroenterologists). Gastroenterologists’ awareness of FMT prior to the survey was much higher than non-gastroenterologists’ (54.3 vs 16.5%, P < 0.001); however, acceptance of FMT was not statistically different (92.4 vs 87.1%, P = 0.1603). Major concerns of FMT included the following: acceptability to patients (79.2%), absence of guidelines (56.9%), and administration and ethics (46.5%). On the basis of understanding, the FMT indications preferred by physicians were recurrent Clostridium difficile infection (86.7%), inflammatory bowel disease combined with Clostridium difficile infection (78.6%), refractory ulcerative colitis (70.9%), ulcerative colitis (65.4%), Crohn’s disease (59.4%), chronic constipation (43.7%), irritable bowel syndrome (39.1%), obesity (28.1%) and type 2 diabetes (23.9%). For donor selection, the majority of physicians preferred individuals with a similar gut flora environment to the recipients. 76.6% of physicians chose lower gastrointestinal tract as the administration approach. 69.2% of physicians considered FMT a safe treatment. CONCLUSION: Chinese physicians have awareness and a high acceptance of FMT, especially gastroenterologists, which provides the grounds and conditions for the development of this novel treatment in China. Physicians’ greatest concerns were patient acceptability and absence of guidelines.

To set up a new method, which is sensitive, low cost, rapid and suitable for clinical application for FTO gene rs9930506 variant genotyping basing on high resolution melting (HRM) platform, and to preliminarily put into practice in susceptibility analysis for metabolic syndrome (MS) in Beijing.Unlabelled probe with C3-spacer block specific for rs9930506 variant has been designed according to the Refseq from GenBank. With LC-Green plus dye pre-mixed, we scanned the signal for the genotype analysis after PCR amplification and HRM reaction. Restriction fragment length polymorphism (RFLP) and PCR-sequencing methods were designed as 2 control genotyping methods for the evaluation of accuracy and convenience. Afterwards, the HRM-based method was put into practice in metabolic syndrome patients (n = 500) and control groups (n = 500) for rs9930506 genotyping, and primarily study the association between rs9930506 and MS.All the 3 methods could genotype rs9930506 appropriately, although the 2 control methods seemed to be a little time-inefficient. The call rate of HRM-method was 100% and sampling accuracy reached 99.3% according to sequencing results. In the MS group, AA, AG and GG genotypes were found in 290, 185 and 25 cases, respectively. And in the control group, those were found in 344, 138 and 18 cases. No genotype distribution difference was detected between control group and HapMap-CHB data (P = 0.520). The genotype distributions were all in Hardy-Weinberg equilibrium in each group. AA genotype of rs9930506 seemed to reduce the risk for MS (OR = 0.626, 95%CI = 0.483 - 0.812).The AA genotype of rs9930506 variant in FTO might be a protective factor for MS in Beijing population. The susceptibility related genotyping in clinical samples could be more rapid, precise and inexpensive with the development of HRM in genotyping.

To investigate the correlation of the common variant single nucleotide polymorphisms (SNP) on chromosome 3 with the incidence and related risk factors of prostate cancer (PCa) in Chinese men.Using the case-control meth- od, we included 124 PCa patients in the PCa group and 111 age- and gender-matched cancer-free healthy subjects as normal controls. We detected the distribution of allele and genotype frequencies of the SNP rs10934853 and rs2660753 with the polymerase chain reaction-high resolution melting curve (PCR-HRM) combined with gene sequencing, analyzed the cumulative effect of the risk genotypes of these two independent variants, and determined the correlation between different genotypes of these two SNPs and clinically related risk factors in the PCa patients.As for the genotypes of rs10934853, there were 28 cases of AA (22.8%), 46 cases of CC (37.4%), and 49 cases of AC (39.8%) in the PCa patients, as compared with 24 (22.0%), 34 (31.2%) and 51 (46.8%) in the healthy controls. As regards the genotypes of rs2660753, there were 13 cases of AA (11.0%), 59 cases of GG (50.0%) and 46 cases of AG (39.0%) in the PCa patients, in comparison with 9 (8.8%), 47 (45.6%) and 47 (45.6%) in the controls. No significant differences were found in the distribution of the genotype and allele frequencies of rs10934853 and rs2660753 between the two groups (P = 0.5200.582). Analysis on the cumulative effect of the risk genotypes of rs10934853 and rs2660753 showed a slightly higher risk of PCa (OR = 1.8311.968) in the two groups with risk genotypes than in the one with wild types (P0.05). Different genotypes of rs10934853 and rs2660753 were not correlated with clinically related risk factors of the PCa patients (P0.05).SNP rs10934853 and rs2660753 on chromosome 3 are not obviously correlated with PCa in Chinese patients, and may not be a genetic risk factor of PCa.

To investigate the symptoms on depression in patients with viral hepatitis.A cross-sectional study was conducted among the patients with viral hepatitis in infectious diseases Hospital of Taiyuan. The questionnaire included a Eysenck Personality Questionnaire, self-rating depression scale (SDS), and a self-designed one related to information regarding general conditions of the disease and social support.(1) Depression symptom prevalence rate among chronic viral hepatitis patients was 54.7% (116/212). (2) Factors as age, occupation, education, confirmed time, number of recurrence and anti-virus treatment, self-confidence on recovery, satisfaction on the surrounding environment etc. that might be associated with depression. (3) The severity of depression was significantly negative correlation with social support scores, objective support scores, subjective support scores (r = -0.262, P = 0.000; r = -0.228, P = 0.001; r = -0.270, P = 0.000). (4) There was positive correlation noticed between severity of the depressive disorder and Eysenck Personality two dimensions scores, while the scores of introversion and extroversion scores were negatively correlated (r = -0.330, P = 0.000) but positively correlated to the emotional stability scores (r = 0.309, P = 0.000).(1) Patients with hepatitis showed symptoms of depression to a certain degree. (2) Factors as age, occupation, education, economic situation, confirmed time of diagnosis, number of recurrence and anti-virus treatments, confidence on recovery, satisfaction on the surrounding environment might be associated with symptoms of depression. (3) There was positive correlation between severity of depressive and Eysenck Personality two dimensions scores but the scores of introversion and extroversion scores were negatively correlated.

We compared clinical data from two related Chinese patients with fatal familial insomnia (FFI) and collected information about their pedigree. The clinical features in the two cases were similar and included initial progressive insomnia and sympathetic activation, which persisted throughout the clinical course. A total of 135 members of this family, across seven generations, were retrospectively investigated. Eleven family members, including the two FFI cases, were found to have died with similar neurological problems. Analysis of PRNP in 32 family members revealed eleven carrying the D178N allele, including the two FFI patients. Spongiform degeneration in brains was not found, but gliosis was obvious in the thalamus of the two cases at postmortem. Proteinase K-resistant prion protein (PrP) was not found in proband's brain by immunohistochemistry, but observed in some areas of brain for both cases by PrP-specific Western blot. Investigation of the pedigree has led to the identification of an additional 9 family members who had similar clinical symptoms and 9 currently healthy individuals with the D178N mutation.

To investigate the epidemiological, genealogic characteristic, familial history of the families with fatal familial insomnia, its clinical and pathological features as well as the heredity rule of related genes.135 familial members of 7 eras were studied. Vein blood samples from patients as well as from some familial members were collected. PRNP gene was studied with PCR, its serial was determined and then authenticated with Nsp I . Brain tissue was obtained for neuropathological test and PrP(Sc) test with Western blot method.Clinical symptoms of the 2 diagnosed cases were typical. 11 familial members died of similar neural disease. 32 samples of their familial members, codon at D178N of PRNP of 11 members was mutated, with mutation rate as 34.38% while D129N showed as methionine. Brain tissue of both probands denaturalized into spongiform and the nerve fiber was absent but PrP(Sc) protein was identified.Genealogy was described in the family with fatal familial insomnia since the patients had typical clinical symptoms and pathological characteristics. It seemed necessary to confirm cases of fatal familial insomnia and their genealogy with epidemiological data and to investigate its gene characteristics as well as with neuropathological and Western blot tests.

To investigate the expression and distribution of intrahepatic CD4+ CD25+ regulatory T cells in immuno-tolerant and immuno-clearance phase of patients with chronic hepatitis B.The expression of FoxP3 was detected in 19 cases of immuno-tolerant phase and 12 cases of immuno-clearance phase by immunohistochemistry. The relation between the intrahepatic expression of FoxP3 and the clinicopathological features were analyzed.The positive signal of FoxP3 is located in nuclear of lymphocyte and mainly aggregated in portal areas as well as occasionally scattered in hepatic sinusoids. The expression of intrahepatic FoxP3 in the group of immuno-tolerant phase was significantly increased than those in normal control (P0.01), and greatly decreased than those in immuno-clearance phase (P0.01). No correlation was observed among the expression of intrahepatic FoxP3, ALT, levels of HBV DNA, HBeAg positive, in patients of immuno-clearance phase, respectively. There were significant differences between immuno-tolerant phase and immuno-clearance phase age, ALT, TBIL, PTA, HBV-DNA and detection of HBeAg but not in sex and family history of HBV infection.CD4+ CD25+ regulatory T cells may play important roles in the clearance of HBV as well as in liver inflammation and injury during chronic HBV infection.

To study the risk factors of hepatitis B virus (HBV) intrauterine infection.Risk factors of HBV intrauterine infection were analyzed by nested case control study.Data from univariate analysis revealed that risk factors of HBV intrauterine infection were positive results on HLA-DR3 (OR = 4.71, 1.62-13.66), HBV DNA (OR = 6.59, 2.72-15.97) and HBeAg (OR = 4.53, 1.93-10.64) in pregnant women, HLA-DR3 (OR = 3.91, 1.18-12.94) in newborn, HLA-I) R3 (OR = 5.96, 1.14-31.15) both in pregnant women and her newborns and HBV infection in placentas (OR = 2.51,1.12-5.60). Results from Multivariate unconditional logistics regression analysis showed that the risk factors of HBV intrauterine infection were positive in both HLA-DR3 (OR = 4.65, 1.44-15.05) and HBV DNA (OR = 6.56, 2.65-16.23) in pregnant women. However, there was no interaction between the two factors. The exposure rate of other factors did not reveal the difference in the two groups. With the increase of HBV DNA in pregnant women, the risk of HBV intrauterine infection was rising (chi2 = 16.74, P0.05).Risk factors of HBV intrauterine infection were HLA-DR3 positive and HBV DNA positive in pregnant women but there was no interaction between the two factors. The risk of HBV intrauterine infection was increased along with the increase of HBV DNA in pregnant women.

To study the expression and distribution of CD4+CD25+ regulatory T cells (Treg) in liver tissues of patients with fibrosing cholestatic hepatitis (FCH) after liver and kidney transplantation and to investigate their roles in the pathogenesis of FCH.Liver biopsy specimens from five patients with FCH were studied histopathologically. A specific marker for CD4+CD25+ regulatory T cells in those specimens was detected with anti-FOXP3 monoclonal antibody by immunohistochemistry. Apoptoses of hepatocytes were detected with in situ apoptosis detection TUNEL kit.Fibrosis in portal and around portal areas, cholestasis in some of the hepatocytes and canaliculi, widespread ballooning and ground-glass appearance of liver cells, and positivity of HBsAg and HBcAg and Pre-S1 protein were seen in the livers of all cases. The positive signal of FOXP3 was located in the cytoplasm of lymphocytes and the positive cells were mainly aggregated in the portal areas as well as occasionally appearing in the hepatic sinusoids. There were many more apoptotic hepatocytes near the portal areas.Fibrosing cholestatic hepatitis has specific pathological characteristics which might be caused by high expressions of FOXP3 in liver tissues.

Based on the clusters growth mechanisms, we study a percolation model where the clusters are assigned to a weight probability function and the intracluster edges are excluded. The weight probability function includes a tunable parameter α. The model can realize the phase transition from continuous to multiple discontinuous and discontinuous as the value of α is tuned. According to the properties of the weight probability function, three typical cases which correspond to different clusters growth mechanisms are analyzed. When the system size N is equal to 1/α, probability modulation effect indicates that the percolation process generates a continuous phase transition which is similar to the classical Erdos—Renyi (ER) network model. At α = 1, it is shown that the lower pseudotransition point is converging to 1 in the thermodynamic limit and the cluster size distribution at the lower pseudotransition point does not obey the power-law behavior, indicating a first-order phase transition. For α = N−1/2, the order parameter exhibits multiple jumps and the magnitude of the jumps are randomly distributed. The numerical simulations find that the relative variance of the order parameter is nonzero on an extended interval. It indicates that the order parameter is non-self-averaging. The cluster size heterogeneity decreases oscillatorily from some moment, which also implies the phenomenon.

To observe the pathology of AIDS-related lymphadenopathy and its relationship to the expression and distribution of CD4 + CD25 + regulatory T cells in lymphoid node tissue.Totally 22 biopsy and 13 autopsy lymphoid node tissues from HIV-positive patients were examined under microscopy and pathological staging was performed. Specific marker for CD4 + CD25 + regulatory T cells in lymphoid node tissue was detected with anti-Foxp3 monoclonal antibody by immunohistochemistry.Among all the 35 specimens, 5, 4, 14, and 12 specimens were histopathologically staged from 1 to 4, respectively. FoxP3 were detected in all lymphoid node tissues. The distribution of FoxP3-positive lymphocytes were mainly in intermediate zone of follicle and cortical area in stages 1 and 2. The counts of FoxP3-positive lymphocytes remarkably decreased in stages 3 and 4, following depletion of lymphocytes.CD4 + CD25 + regulatory T cells exist in lymphoid node tissue of patients with HIV infection. Their amounts decrease or deplete along with the progression of AIDS-related lymphadenopathy.

Due to the structural and functional importance of tight turns, some methods have been proposed to predict gamma-turns, beta-turns, and alpha-turns in proteins. In the past, studies of pi-turns were made, but not a single prediction approach has been developed so far. It will be useful to develop a method for identifying pi-turns in a protein sequence. In this paper, the support vector machine (SVM) method has been introduced to predict pi-turns from the amino acid sequence. The training and testing of this approach is performed with a newly collected data set of 640 non-homologous protein chains containing 1931 pi-turns. Different sequence encoding schemes have been explored in order to investigate their effects on the prediction performance. With multiple sequence alignment and predicted secondary structure, the final SVM model yields a Matthews correlation coefficient (MCC) of 0.556 by a 7-fold cross-validation. A web server implementing the prediction method is available at the following URL: http://210.42.106.80/piturn/.

Severe acute respiratory syndrome (SARS) is an emerging infectious disease that first manifested in humans in November 2002. The SARS-associated coronavirus (SARS-CoV) has been identified as the causal agent, but the pathology and pathogenesis are still not quite clear.Post-mortem lung samples from six patients who died from SARS from April to July 2003 were studied by light and electron microscopy, Masson trichromal staining and immunohistochemistry. Evidence of infection with the SARS-CoV was determined by reverse-transcription PCR (RT-PCR) , serological examination and electron microscopy.Four of six patients had serological and RT-PCR evidence of recent infection of SARS-CoV. Morphologic changes are summarized as follows: (1) Diffuse and bilateral lung consolidation was seen in all patients (6/6) with increasing lung weight. (2) Diffuse alveolar damage was universal (6/6) with hyaline membrane formation (6/6), intra-alveolar edema/hemorrhage (6/6), fibrin deposition (6/6), pneumocyte desquamation (6/6). A marked disruption in the integrity of the alveolar epithelium was confirmed by immunostaining for the epithelial marker AE1/AE3 (6/6). (3) Type II pneumocytes, with mild hyperplasia, atypia, cytomegaly with granular amphophilic cytoplasm and intracytoplasmic lipid accumulation (5/6). (4) Giant cells in the alveoli were seen in five of 6 patients (5/6) , most of which were positive for the epithelial marker AE1/AE3 (5/6), but some cells were positive for the macrophage marker CD68(2/6). (5) A pronounced increase of macrophages were seen in the alveoli and the interstitium of the lung (6/6), which was confirmed by histological study and immunohistochemistry. (6) Haemophagocytosis was present in five of the 6 patients(5/6). (7) Lung fibrosis was seen in five patients(5/6), with alveolar septa and interstitium thickening(5/6), intraalveolar organizing exudates (6/6) and pleura thickening (4/6). Proliferation of collagen was confirmed by Masson trichromal staining, most of which was type III collagen by immunostaining. The formation of distinctive fibroblast/myofibroblast foci was seen in five patients (5/6) by light microscopy and immunochemistry. (8) Squamous metaplasia of bronchial mucosa was seen in five patients(5/6). (9) Thrombi was seen in all patients(6/6). (10) Accompanying infection was present in two patients, one was bacteria, the other was fungus. In addition, electron microscopy revealed viral particles in the cytoplasm of alveolar epithelial cells and endothelial cells corresponding to coronavirus.Direct injury of SARS-CoV on alveolar epithelium, prominent macrophage infiltration and distinctive fibroblast/myofibroblast proliferation may play major roles in the pathogenesis of SARS.

To study the pathological changes of the liver tissues of patients with HIV infection.14 biopsy and 12 autopsy liver tissues were examined histologically. HIV-1 related antigen of outer membrane protein gp120 and capsid protein p24 were examined with their corresponding monoclonal antibodies by immunohistochemistry.In the biopsy group, cytomegalic virus (CMV) infection was found in one (1/14) case, outer membrane protein gp120 and/or capsid protein p24 antigen were detected in Kupffer cells and in some of the lymphocytes in 11 cases. All the hepatocytes were negative for outer membrane protein gp120 and capsid protein p24 antigens. In the autopsy group, there were 5 (5/12) cases of liver tissues with CMV infection and 5 cases each with mycobacterium and Toxoplasma gondii infection. Capsid protein p24 was detected in liver tissues in 3 cases.There is HIV infection in liver tissue of patients with HIV. The rate of opportunistic infections in liver biopsy samples was lower than that in the autopsy liver tissues of patients with HIV.

A base population was established through multi-parent random crossing by using Taigu dominant male-sterile wheat, and then five cycles of 2-way selection for four quantitative characters were conducted. The dynamic changes of genetic structures in the open-pollinated wheat population were examined by RAPD technique. Seven primers in RAPD analysis amplified 116 sites. The results of gene frequencies and phenotypic bands showed abundant genetic variations existed in the population. The percentage of polymorphic loci was 88.79, and the average heterozygosity was 0.3143 in the whole population. The genetic distance of RAPD showed as follows: (1) The genetic distance within a subpopulation was lower than that between every two subpopulations. (2) Each subpopulation had considerable divergence compared with unselected population. (3) The genetic distances between the subpopulations which were selected for plant height gradually increased accompanied with the selection. (4) The genetic distance between subpopulations which were selected for the same character was lower than that were selected for different characters both in the same generation and among different generations. The cluster results of RAPD genetic distance demonstrated that the subpopulations selected for the same character going to one cluster. It also showed that the selective effect of increasing plant height was obvious.

Hairpin structure of DNA molecules has been widely employed in a variety of biosensors and in nanoscale molecular assembly applications. For example, the well known molecular beacons can report the presence of specific nucleic acids in homogeneous solutions with high accuracy. Recently, Smith et al. proposed the induction of hairpin formation through sequence-specific binding of a small-molecule ligand to a G-G mismatch. Not only did this method offer great flexibility in controlling hairpin formation, more importantly the induced hairpin maintains high degree of sensitivity toward specific hybridization. In this contribution, we present a theoretical model for the logical NAND gate based on induced hairpin formation.

We extend the Achlioptas percolation (AP) process [Achlioptas et al. Science 323 (2009) 1453] to two generalized Achlioptas percolation processes named GAP1 and GAP2. GAP1 induces a weighted probability factor α in the node sampling process and excludes the intracluster links. Based on GAP1, GAP2 requires m pairs of nodes sampled to add m candidate links that should be residing in 2m different clusters at each step. In the evolution of GAP1, the phase transition can evolve from the continuous to the 'most explosive' percolation as the value of the factor α is decreasing to a certain negative number. It indicates that there might be a type of discontinuous transition induced by the probability modulation effect even in the thermodynamic limit, and the most explosive percolation is only one of its extreme cases. We analyze the characteristics of the evolving process of the two-nodes-clusters and the cluster-size distribution at the transformation point for different α; the numerical results suggest that there might be a critical value α0 and the phase transition should be discontinuous (α ≤ α0) or continuous (α > α0). In the evolution of GAP2, twice phase transitions are observed successively and the time duration between them becomes shorter till they amalgamate into the 'most explosive' percolation. The first transition is induced by the probability modulation effect analyzed in GAP1, the second transition, induced by the three coexisting giant clusters, is always discontinuous and the maximum jump of order parameter approaches N/3 while the value of the factor α is increasing to 1.4 approximately. In this work, two typical discontinuous transitions induced respectively by the probability modulation and the extended local competition are exhibited in GAP2, which might provide references to analyze the discontinuous phase transition in networks further.

We present a percolation process in which the classical Erdos—Renyi (ER) random evolutionary network is intervened by the product rule (PR) from some moment t0. The parameter t0 is continuously tunable over the real interval [0, 1]. This model becomes the random network under the Achlioptas process at t0 = 0 and the ER network at t0 = 1. For the percolation process at t0 ≤ 1, we introduce a relatively slow-growing point, after which the largest cluster begins growing faster than that in the ER model. A weakly discontinuous transition is generated in the percolation process at t0 ≤ 0.5. We take the relatively slow-growing point as the lower pseudotransition point and the maximum gap point of the order parameter as the upper pseudotransition point. The critical point can be approximately predicted by each fitting function of the two points about t0. This contributes to understanding the rapid mergence of the large clusters at the critical point. The numerical simulations indicate that the lower pseudotransition point and the upper pseudotransition point are equal in the thermodynamic limit. When t0 > 0.5, the percolation processes generate a continuous transition. The scaling analyses of several quantities are presented, including the relatively slow-growing point, the duration of the relatively slow-growing process, as well as the relatively maximum strength between the percolation percolation at t0 < 1 and the ER network about different t0. The presented mechanism can be viewed as a two-stage percolation process that has many potential applications in the growth processes of real networks.

To protect carbon/carbon (C/C) composites against oxidation at 1 500 °C in a wind tunnel, a multi-layer coating was prepared on them by a combination of pack cementation, chemical vapor deposition and slurry coating. X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy were used to analyze the phase, microstructure and elemental distribution of the coating. Results show that a three-layer structure is formed including a multi-phase MoSi 2 -SiC-Si inner layer, a SiC middle layer and a borosilicate glass outer layer with thicknesses of about 80, 20 and 80 μm, respectively. The three-layer coating can protect the C/C composites from failure at 1500 °C for 53 h in a wind tunnel. The cracking of the coating by thermal shock and gas-fired impact is the main cause for the failure of the coating.