Clinical effectiveness of semaglutide on weight loss, body composition, and muscle strength in Chinese adults

OBJECTIVE

The aim of this study was to investigate the clinical effectiveness of semaglutide on weight loss, body composition and muscle strength in the Chinese population with obesity.

PATIENTS AND METHODS

Data were retrospectively analyzed for participants prescribed semaglutide in 2021 and 2022 from a Chinese weight management clinic. Changes in weight, body composition, biochemical indicators, calf circumference and handgrip strength were collected. Body fat and skeletal muscle were also measured using the bioelectrical impedance analysis. Paired t-test was used to compare the values after 6 months of treatment with the baseline values.

RESULTS

A total of 53 obese patients received 24 weeks of lifestyle intervention plus semaglutide treatment. 10 patients who failed to adhere to the follow-up were excluded, and 43 patients were studied. The average baseline body mass index (BMI) was 33.0 kg/m2, and the average body weight was 90.0 kg. After 6 months of treatment, the patient's weight was significantly reduced by 9.9 ± 3.9 kg (p < 0.001), and the weight loss percentage was 11.2 ± 4.5% (p< 0.001). The proportion of patients with weight loss ≥ 5% and ≥ 10% was 93% and 54%, respectively. Fasting blood glucose, fasting insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) index, blood uric acid and blood lipid levels also decreased after treatment. Body composition analysis showed that the loss of skeletal muscle mass was 1.4 ± 1.3 kg (p < 0.001), which was significantly less than the loss of fat mass of 5.6 ± 3.7 kg (p < 0.001). By percentage, the fat mass loss was 15.6 ± 10.1%, and the muscle mass loss was 4.8 ± 4.4% (p < 0.001). The visceral fat area was significantly reduced by 24.4 ± 17.7 cm (p < 0.001). There was no significant change in skeletal muscle index (8.1 ± 1.0 kg/m2 at baseline and 7.9 ± 1.0 kg/m2 at 24 weeks). The calf circumference (42.6 ± 3.6 cm at baseline, 41.2 ± 3.8 cm at 24 weeks) and grip strength (33.3 ± 9.5 kg at baseline, 32.3 ± 9.0 kg at 24 weeks) did not decrease significantly. The main adverse reactions were mild gastrointestinal dysfunction (nausea, diarrhea and vomiting), without ketoacidosis.

CONCLUSIONS

In a real-world setting, semaglutide can reduce the weight and fat of obese patients while effectively maintaining muscle mass and muscle strength.

[Immune-related genes and their determined immune cell microenvironment to predict the prognosis of gastric adenocarcinoma]

Objective: Through bioinformatics analysis to screen key immune-related genes (IRGs) and cancer-related pathways in gastric adenocarcinoma (GAC) therapy, combining immune cell microenvironment to predict the prognosis of GAC. Methods: RNA sequencing and clinical data were obtained from public databases. Differentially expressed IRGs between GAC and normal tissues were identified by integrated bioinformatics analysis. Univariate and multivariate Cox regression analyses were applied to screen survival-associated IRGs. Then, we established the risk signature model and found another database for external validation. In addition, we explored the relationship with the immune cell microenvironment in each GAC sample using CIBERSORT algorithms. Results: A total of 78 differentially expressed IRGs were screened, including 47 up-regulated and 31 down-regulated genes. Subsequently, a five-IRGs signature (BMP8A、MMP12、NRG4、S100A9 and TUBB3) was significantly associated with the overall survival of GAC patients. Survival analysis indicated that patients in the high-risk group have a poor prognosis. The results of the multivariate analysis revealed that the risk score was an independent prognostic factor. Further analysis showed that the prognostic model had excellent predictive performance in both TCGA and GEO validated cohorts. Besides, the results of tumor-infiltrating immune cell analysis indicated that the risk score could reflect the status of the tumor immune microenvironment. Conclusion: BMP8A, MMP12, NRG4, S100A9 and TUBB3 with the risk signature model are associated with prognosis in patients with GAC, combined with tumor-infiltrating immune cells to provide new markers for immunotherapy in GAC.

[Transoral endoscopic resection of benign tumors in parapharyngeal space via medial pterygomandibular raphe approach]

Objective: To explore the surgical methods and effects of transoral endoscopic resection of benign tumors in parapharyngeal space via medial pterygomandibular raphe approach. Methods: The clinical data of 23 patients who underwent resection of benign tumors in parapharyngeal space by endoscopic medial pterygomandibular raphe approach from January 2016 to July 2020 in the Department of Otorhinolaryngology Head and Neck Surgery, the Affiliated Hospital of Qingdao University were analyzed retrospectively. There were 14 males and 9 females with a median age of 43 years. The tumors were located in the anterior space of the styloid process in 13 cases and in the posterior space in 10 cases. The smallest tumor volume was 7.3 ml and the largest was 80.2 ml. The preoperative imaging features, the characteristics and risks of this approach in the operation were analyzed, and the feasible mode of operation was explored. Results: All patients completed the operation successfully. The intraoperative blood loss was 20 to 50 ml, with an average of 28.3 ml. The operation time was 40 to 110 min, with an average of 75.4 min. The incision length was 2 to 4 cm, with an average of 3.0 cm. The postoperative pain score was 2 to 4, with an average of 3.2. The postoperative hospital stay was 4 to 9 d, with an average of 6.7 d. Postoperative pathological diagnosis included pleomorphic adenoma (n=12), neurilemmoma (n=10) and basal cell adenoma (n=1). The patients were followed up for 6 to 60 months. There was no postoperative complication such as infection or serious bleeding, and there was no tumor recurrence after operation. Conclusion: Endoscopic resection of benign tumor in parapharyngeal space via medial pterygomandibular raphe approach is a safe, effective, and minimally invasive surgical method for the treatment of tumors in parapharyngeal space.

Comprehensive analysis of lncRNA-mediated ceRNA network in papillary thyroid cancer

OBJECTIVE

Papillary thyroid cancer (PTC) is one type of thyroid cancer. Although it has a good prognosis, the recurrence and metastasis rates remain high.

MATERIALS AND METHODS

The microarray dataset GSE66783 was downloaded from the Gene Expression Omnibus (GEO). With the R package, the differentially expressed genes (DEGs) and lncRNAs between normal adjacent tissues and cancer tissues of PTC were identified. The miRNAs that were targeted by DElncRNAs and the mRNAs that were targeted by miRNAs were discovered through miRcode and through miRTarBase, TargetScan, and miRDB, respectively. Furthermore, the ceRNA network was constructed. GO and KEGG enrichment analyses were performed on the DEGs. The PPI network of the DEGs was obtained from the STRING database, and the top 5 hub genes that had a tight correlation with the disease were obtained by using Cytoscape. Finally, the study used the Kaplan-Meier method to analyze PTC patient survival time, and the Human Protein Atlas database was used to retrieve the expression of the hub genes in normal and PTC patient tissues.

RESULTS

Five hub genes showed significant differences in expression in the PPI network, and 12 lncRNA-miRNA-mRNA pathways might participate in the potential pathophysiological process of PTC.

CONCLUSIONS

The study indicated that these ceRNAs might contribute to future therapies for PTC.

MiR-374b reduces cell proliferation and cell invasion of cervical cancer through regulating FOXM1

OBJECTIVE

Deregulation of microRNAs (miRNAs) has been identified as critical event in tumor initiation and progression. We aimed to explore the role of miR-374b in cervical cancer progression.

PATIENTS AND METHODS

MiR-374b expression was detected using qRT-PCR in cervical cancer tissues compared with normal counterparts. Cell proliferation and invasion ability were detected using Cell Counting Kit-8 (CCK8) cell proliferation and transwell invasion assay. Dual luciferase reporter assay, qRT-PCR, and Western blot analysis were used to demonstrate that FOXM1 was a target of miR-374b.

RESULTS

We demonstrated that downregulation of miR-374b was frequently examined in cervical cancer tissues compared with normal counterparts. Furthermore, we showed the lower miR-374b expression associated with lymph node metastasis and advanced FIGO stage in patients with cervical cancer. Furthermore, ectopic expression of miR-374b could significantly decrease cell proliferation and invasion ability. However, inhibition of miR-374b had opposite effects. Dual luciferase reporter assay, qRT-PCR, and Western blot analysis revealed that miR-374b overexpression suppressed cell proliferation and invasion ability via affecting FOXM1 expression.

CONCLUSIONS

These results indicated that miR-374b acted as tumor suppressor and may serve as a potential target for cervical cancer treatment.

[The role and significance of digital reconstruction technique in liver segments based on portal vein structure]

Objective: To study the segment of liver according to the large amount of three-dimensional(3D) reconstructive images of normal human livers and the vascular system, and to recognize the basic functional liver unit based on the anatomic features of the intrahepatic portal veins. Methods: The enhanced CT primitive DICOM files of 1 260 normal human livers from different age groups who treated from October 2013 to February 2017 provided by 16 hospitals were analyzed using the computer-aided surgery system.The 3D liver and liver vascular system were reconstructed, and the digital liver 3D model was established.The vascular morphology, anatomical features, and anatomical distributions of intrahepatic portal veins were statistically analyzed. Results: The digital liver model obtained from the 3D reconstruction of CAS displayed clear intrahepatic portal vein vessels of level four.Perform a digital liver segments study based on the analysis of level four vascular distribution areas.As the less anatomical variation of left hepatic portal vein, the liver was classified into four types of liver segmentation mainly based on right hepatic portal vein.Type A was similar to Couinaud or Cho's segmentation, containing 8 segments(537 cases, 42.62%). Type B contained 9 segments as there are three ramifications of right-anterior portal vein(464 cases, 36.82%). The main difference for Type C was the variation of right-posterior portal vein which was sector shape(102 cases, 8.10%). Type D contained the cases with special portal vein variations, which needs three-dimensional simulation to design individualized liver resection plan(157 cases, 12.46%). These results showed that there was no significant difference in liver segmental typing between genders(χ(2)=2.179, P=0.536) and did not reveal any significant difference in liver segmental typing among the different age groups(χ(2)=0.357, P=0.949). Conclusions: The 3D digital liver model can demonstrate the true 3D anatomical structures, and its spatial vascular variations.The observation of anatomic features, distribution areas of intrahepatic portal veins and individualized liver segmentation achieved via digital medical 3D visualization technology is of great value for understand the complexity of liver anatomy and to guide the precise hepatectomy.

Mode instability in ytterbium-doped non-circular fibers

We present a theoretical study of transverse mode instability (TMI) in non-circular ytterbium-doped fibers including the rectangular core in a circular or D-shaped cladding. The D-shaped cladding is found efficient to suppress the TMI thanks to better heat dissipation, as compared to the circular cladding. However, the rectangular core does not suppress the TMI despite its better heat dissipation than a circular core counterpart. Although the temperature built in the rectangular core decreases with an increasing aspect ratio of the rectangular core, the low temperature does not benefit the TMI suppression. Instead, the TMI becomes stronger than its circular core counterpart. Our study reveals that the power coupling between two involved modes and gain saturation effect play a significant role in influencing the TMI. The power coupling strength is associated with the frequency offset between two modes, and it grows with an increasing aspect ratio of rectangular cores, suggesting the longer axis of rectangular core promotes the TMI.

The prevalence of latent tuberculosis infection in rural Jiangsu, China

OBJECTIVES

Diagnosis and interventional treatment of latent tuberculosis (TB) infection (LTBI) are important components in tuberculosis control. But systematic studies regarding the epidemic of LTBI are still rare in China. The objective of this study was to assess the prevalence and risk factors associated with LTBI based on the results of a domestic TB-specific gamma interferon (IFN-γ) release assay (TB-IGRA) in rural Jiangsu, China.

STUDY DESIGN

Cross-sectional study of subjects registered in eight villages in Jiangsu, China.

METHODS

This study was conducted in 2012 in eight villages. After recruitment, individuals with active TB or a history of TB were excluded. The TB-IGRA was performed for diagnosis of LTBI.

RESULTS

2169 of 2185 subjects met the requirement and were analysed in this study. 524 (24.3%) had a positive result, and positive rate gradually increased with age (P for trend <0.001). Multivariate analyses showed that increasing age, male gender and a history of TB exposure were risk factors associated with LTBI. Bacillus Calmette-Guérin (BCG) vaccination did not reduce the risk of TB infection in participants (aged ≥20 years).

CONCLUSIONS

The findings of this study demonstrate that the prevalence of LTBI in China might be overestimated by tuberculin skin test compared with IFN-γ release assay (IGRA). The degree of TB exposure is related to Mycobacterium tubercuium (MTB) infection, and BCG vaccination offers little protection against MTB infection in adults. The early and effective detection and treatment of active TB patients, and screening and intervention for LTBI patients with a high risk of developing active TB could be cost-effective methods for TB control in China.

Advancing research and clinical care in the management of neuropathic pain after spinal cord injury: Key findings from a Canadian summit

Background: Optimal management of neuropathic pain (NP) is essential to enhancing health-related quality of life for individuals living with spinal cord injury (SCI). A key strategic priority for the Ontario Neurotrauma Foundation (ONF) and Rick Hansen Institute (RHI) is optimizing NP management after SCI.

Aims: A National Canadian Summit, sponsored by ONF and RHI, was held to develop a strategic plan to improve NP management after SCI.

Methods: In a one-day meeting held in Toronto, Ontario, a multidisciplinary panel of 18 Canadian stakeholders utilized a consensus workshop methodology to (1) describe the current state of the field, (2) create a long-term vision, and (3) identify steps for moving into action.

Results: A review of the current state of the field identified strengths including rigourously developed evidence syntheses and practice landscape documentation. Identified gaps included limited evidence on NP hindering recommendation development in evidence syntheses, absence of a national strategy, care silos with limited cross-continuum connections, limited consumer involvement, and limited practice standard implementation. The panel identified key themes for a long-term vision to improve the management of SCI NP in Canada, including establishing an integrated collaborative network; standardized care and outcome evaluation; education; advocacy; and directing resources to innovative solutions. The panel identified the next step as prioritization of areas that will have the greatest impact in a 5-year time frame.

Conclusion: A strategic plan outlining a long-term vision to improve management of NP after SCI in Canada was developed and will inform future activities of the sponsors.

Hepatic adenylate cyclase 3 is upregulated by Liraglutide and subsequently plays a protective role in insulin resistance and obesity

OBJECTIVE

Recent studies have demonstrated that adenylate cyclase 3 (AC3) has a protective role in obesity. This gene resides at the pathway with glucagon-like peptide (GLP)-1. Liraglutide is a GLP-1 analog and has independent glucose and body weight (BW)-reducing effects. In the present study, we aimed to examine whether hepatic AC3 activity was regulated by Liraglutide and to further understand the effect of AC3 in reduction of BW and insulin resistance.

SUBJECTS

The diabesity and obese mice were induced from db/db and C57BL/6 J mice, respectively, by high-fat diet. Liraglutide (0.1 mg kg(-1) per 12 h) was given to the mice twice daily for 12 weeks. C57BL/6 J mice fed with chow diet and obese or diabesity mice treated with saline were used as the controls. Hepatic AC3 gene expression at mRNA and protein levels was analyzed with real-time reverse transcription-PCR and western blot. Fasting blood glucose and serum insulin levels were measured and followed insulin resistance index (HOMA-IR) was evaluated according to the homeostasis model assessment.

RESULTS

After administration of Liraglutide, BW and HOMA-IR in obese and diabesity mice were decreased, whereas hepatic AC3 mRNA and protein expression levels were upregulated. The AC3 gene expression was negatively correlated with BW, HOMA-IR and the area ratio of hepatic fat deposition in the liver.

CONCLUSIONS

The present study thus provides the evidence that hepatic AC3 gene expression is upregulated by Liraglutide. The reduction of BW and improvement of insulin resistance with Liraglutide may be partially explained by AC3 activation.

Social isolation-induced epigenetic changes in midbrain of adult mice

Social isolation and loneliness increase the risk of death as much as well-established risk factors for mortality such as cigarette smoking and alcohol consumption. The underlying molecular mechanisms are poorly understood. In the present study, 3 months old male C57BL/6 mice were socially isolated by individual housing for another 3 months. At the age of 6 months, epigenetic changes were analyzed in midbrain. Social isolation of male adult mice led to an increased global DNA methylation, which was associated with enhanced activity of DNA methyltransferase. Di- and trimethylation of global histone H3 lysine 4 (H3K4) were increased in midbrain of socially isolated mice, accompanied by enhanced H3K4 histone methyltransferase activity. In addition, social isolation of adult mice led to activation of histone acetyltransferases as well as of histone deacetylases (HDAC) resulting in a net enhancement of histone H3 lysine 9 (H3K9) acetylation. Gene-specific effects were observed for Hdac1, Hdac3 and the serotonin transporter Slc6a4. Social isolation led to an up-regulation of Hdac1 and Hdac3, associated with decreased DNA methylation in the CpG island of the respective genes. On the contrary, the Slc6a4 gene was down-regulated, which was associated with enhanced DNA methylation. Collectively, the results from the present study demonstrate for the first time that social isolation of adult mice leads to a wide range of global epigenetic changes and these effects may have profound impact on gene expression pattern and phenotype of the socially isolated animals.

Decreased expression of microRNA-375 in nonsmall cell lung cancer and its clinical significance

OBJECTIVE

Emerging evidence has shown the association of aberrant microRNA-375 (miR-375) expression with tumourigenesis in many types of human malignancy. This prospective study characterized the contribution of miR-375 to the initiation and progression of nonsmall cell lung cancer (NSCLC).

METHODS

The real-time reverse transcription-polymerase chain reaction was used to examine miR-375 levels prospectively in 96 pairs of samples of NSCLC tissue and adjacent noncancerous tissue (> 2 cm from cancer tissue). The relationship between miR-375 levels and clinico pathological features was also explored.

RESULTS

MiR-375 was downregulated in 89% (85/96) of NSCLC samples compared with matched noncancerous tissue samples. Decreased miR-375 correlated significantly with advanced disease stage and lymphatic metastasis. Univariate and multivariate Cox proportional hazard regression analyses revealed that underexpression of miR-375 was an unfavourable prognostic factor for overall survival in NSCLC.

CONCLUSIONS

This study suggested that miR-375 is a novel prognostic indicator in NSCLC and might be a potential target for diagnosis and gene therapy.

SERS Titration of 4-Mercaptopyridine Self-Assembled Monolayers at Aqueous Buffer/Gold Interfaces

Determination of the surface pK(a) of self-assembled monolayers (SAMs) at aqueous buffer/gold interfaces using surface-enhanced Raman scattering (SERS) measurements, namely, SERS titration, is reported for the first time. From the analysis of pH-dependent SERS spectra of 4-mercaptopyridine monolayers on gold, the pK(1/2) (3.9 ± 0.2) was determined. By further correlating the surface pH value with the bulk pH value in terms of the Gouy-Chapmann model, the surface pK(a) (5.3 ± 0.3) was evaluated accordingly. Compared to the conventional contact angle titration, SERS titration has the advantage of giving further insight into the microscopic and dynamic information of the surface-confined functional groups. In addition, such a technique has high sensitivity, micrometer spatial resolution, and chemical selectivity.

Serological survey of antibodies to influenza A viruses in a group of people without a history of influenza vaccination

A serological survey for antibodies to influenza viruses was performed in China on a group of people without a history of influenza vaccination. Using the haemagglutination inhibition (HI) assay, we found seropositivity rates for seasonal H3N2 to be significantly higher than those for seasonal H1N1. Samples positive for antibodies to the pandemic (H1N1) 2009 virus increased from 0.6% pre-outbreak to 4.5% (p <0.01) at 1 year post-outbreak. Interestingly, HI and neutralization tests showed that 1.4% of people in the group have antibodies recognizing H9N2 avian influenza viruses, suggesting that infection with this subtype may be more common than previously thought.

[Studies on DNA amplification fingerprinting of cortex Magnoliae officinalis]

Total genomic DNA samples of Chinese traditional medicine(CTM) Cortex Magnoliae Officinalis ("Houpo"), its counterfeits and substitutes were amplified by DNA amplification fingerprinting(DAF). Their amplified DNA banding patterns were distinguished on PAGE. The results show that DAF can be used to identify CTM "Houpo", its counterfeits and substitutes, which is also quite valuable for correctly introducing original plant.

[Prevention of early postoperative increase in intraocular pressure after phacoemulsification. Comparison of different antiglaucoma drugs]

PURPOSE

To compare the ocular hypotensive effect of different antiglaucomatous eye drops.

PATIENTS AND METHODS

This double-blind, randomized study included 119 eyes of 119 patients without other ocular pathology undergoing standardized (one surgeon, Healon) small incision cataract surgery with foldable intraocular lens implantation. The patients were assigned to one of five groups: group 1: 0.25% timolol in Gelrite (extended efficacy, n = 23); group 2: 2% dorzolamide (n = 24); group 3: combination of 0.5% timolol plus 2% dorzolamide (n = 22); group 4: brimonidine (n = 26); group 5: gentamicin (control, n = 24). Intraocular pressure (IOP) was measured preoperatively and at 3 +/- 1, 6 +/- 1, 9 +/- 1, 24 +/- 3, and 48 +/- 3 h postoperatively. Statistical interference was determined by nonparametric group comparisons using Wilcoxon's tests. Absolute values (static comparison) and intraindividual differences from preoperative measurements (dynamic comparisons) were evaluated. All p values should be regarded as descriptive values since they were not formally adjusted for multiplicity. A p value lower than 0.05 therefore indicates local statistical significance.

RESULTS

There were no differences between the groups with regard to age, phacoemulsification time, axial length, and preoperative IOP. A statistically significant IOP decrease was measured in group 1 at 24 (p = 0.028) and 48 h (p = 0.007) and in group 3 at 3 (p = 0.001), 6 (p = 0.001), 24 (p = 0.001), and 48 h (p = 0.001) after surgery. A statistically significant IOP increase occurred in group 4 at 3 (p = 0.001), 6 (p = 0.001), and 9 h (p = 0.001) and in group 5 at 3 (p = 0.001), 6 (p = 0.001), 9 (p = 0.001), and 24 h (p = 0.002) postoperatively. Groups 1, 2, and 3 demonstrated lower IOPs at different time points in comparison to groups 4 and 5. Furthermore, group 3 had lower IOPs at 3 h (compared to group 1) and at 6 h (compared to group 2) postoperatively. No statistical differences in IOP were found after 48 h.

CONCLUSION

The results favor a combination of 0.5% timolol plus 2% dorzolamide to control postoperative IOP elevation.

[A therapeutical approach by administering reduced glutathione to patients with uremic anemia]

OBJECTIVE

To verify the therapeutical effect of exogenous reduced glutathione (GSH) on the patients with uremic anemia.

METHODS

Forty two patients with uremic anemia were randomly divided into treatment group and control group. All patients received subcutaneously recombinant human erythropoietin (r-HuEPO) at the dose of 3000U twice a week for 12 weeks. Each of the patients in the treatment group was given intravenously reduced glutathione at the dose of 1200 mg twice a week for 12 weeks. The measurements of hemoglobin, red blood cells and hematocrit were performed.

RESULTS

After administration of r-HuEPO, the levels of hemoglobin, red blood cells and hematocrit were significantly elevated in both treatment and control groups (P < 0.01). The levels of hemoglobin, red blood cells and hematocrit in treatment group were elevated much more obviously, compared with those in control group (P < 0.05).

CONCLUSION

These findings seem to indicate that exogenous GSH could enhance the effect of r-HuEPO on uremic anemia, and therefore it might represent a useful drug in the treatment and management of uremic anemia.

cDNA cloning and sequence analysis of hepatitis G virus genome isolated from a Chinese blood donor

OBJECTIVE

To obtain full-length sequence of a Chinese hepatitis G virus (HGV) strain (HGVch) and investigate the genetic characteristic of HGVch and its identity to other isolates.

METHODS

Reverse transcription (RT) and nested-PCR were used to screen HGV RNA positive serum and amplify cDNA fragments. A positive serum without known hepatitis virus markers was selected for isolating HGV RNA template. The HGV genome was divided into 12 overlapping fragments and directly cloned into pGEM-T vector. Sequences were determined by dideoxy terminus-end method of DNA sequencing and then analyzed by computer.

RESULTS

The twelve fragments of HGVch cover 9213 nucleotides in length, containing a large open reading frame (ORF) encoding 2873 animo acids polyprotein that began with a methonine residue and ended at termination codon. HGVch is about 86.5%-89.5% identical to other known HGV isolates at the nucleotide level and about 93.9%-96.2% at the deduced animo acid level.

CONCLUSION

HGV is a non-A-E hepatitis causal agent, proved to be related with posttransfusion hepatitis in all over the world. Chinese HGV isolate has very close relationship to other isolates from Africa, Europe, Japan, without significant difference across the entire genome. It is suggested that the sequences of HGV isolates are very conservative and the evolution is very slow.

SERS Titration of 4-Mercaptopyridine Self-Assembled Monolayers at Aqueous Buffer/Gold Interfaces

Determination of the surface pK(a) of self-assembled monolayers (SAMs) at aqueous buffer/gold interfaces using surface-enhanced Raman scattering (SERS) measurements, namely, SERS titration, is reported for the first time. From the analysis of pH-dependent SERS spectra of 4-mercaptopyridine monolayers on gold, the pK(1/2) (3.9 ± 0.2) was determined. By further correlating the surface pH value with the bulk pH value in terms of the Gouy-Chapmann model, the surface pK(a) (5.3 ± 0.3) was evaluated accordingly. Compared to the conventional contact angle titration, SERS titration has the advantage of giving further insight into the microscopic and dynamic information of the surface-confined functional groups. In addition, such a technique has high sensitivity, micrometer spatial resolution, and chemical selectivity.

[Identification of hepatitis C or/and G virus RNA in one tube by reverse transcription nested polymerase chain reaction]

Hepatitis C and G viruses belong to the flaviviridae family. They have similar modes of transmission. The dual infection of HGV and HCV were reported. A simultaneous detection for HCV or/and HGV was established by reverse transcription nested polymerase chain reaction(RT-nested PCR). The primers were derived from the 5' non-coding region of HCV and NS3 region of HGV, and the length of the PCR product was between 170 bp and 300 bp. RT-nested PCR can be finished in one test tube and HGV and/or HCV can be detected simultaneously in one RT-nest PCR. 153 samples were detected by his method. Our results showed that the established assay is useful for screening and identification of HCV or/and HGV RNA. This method is simple and specific practicable.