Colorimetric and photothermal dual-mode lateral flow immunoassay based on Au-Fe3O4 multifunctional nanoparticles for detection of Salmonella typhimurium.

Au-Fe3O4 multifunctional nanoparticles (NPs) were synthesized and integrated with lateral flow immunoassay (LFIA) for dual-mode detection of Salmonella typhimurium. The Au-Fe3O4 NPs not only combined excellent local surface plasmon resonance characteristics and superparamagnetic properties, but also exhibited good photothermal effect. In the detection, antibody-conjugated Au-Fe3O4 NPs first captured S. typhimurium from complex matrix, which was then loaded on the LFIA strip and trapped by the T-line. By observing the color bands with the naked eyes, qualitative detection was performed free of instrument. By measuring the photothermal signal, quantification was achieved with a portable infrared thermal camera. The introduction of magnetic separation achieved the enrichment and purification of target bacteria, thus enhancing the detection sensitivity and reducing interference. This dual-mode LFIA achieved a visual detection limit of 5 × 105 CFU/mL and a photothermal detection limit of 5 × 104 CFU/mL. Compared with traditional Au-based LFIA, this dual-mode LFIA increased the detection sensitivity by 2 orders of magnitude and could be directly applied to unprocessed milk sample. Besides, this dual-mode LFIA showed good reproducibility and specificity. The intra-assay and inter-assay variation coefficients were 3.0% and 7.9%, and with this dual-mode LFIA, other bacteria hardly produced distinguishable signals. Thus, the Au-Fe3O4 NPs-based LFIA has potential to increase the efficiency of pandemic prevention and control. Au-Fe3O4 nanoparticle proved to be a promising alternative reporter for LFIA, achieving multifunctions: target purification, target enrichment, visual qualitation, and instrumental quantification, which improved the limitations of traditional LFIA.

Celiac disease may be rare among children in South China.

OBJECTIVE: The prevalence of celiac disease (CD) varies geographically and ethnically; however, the prevalence among children in South China remains unknown. We therefore determined the occurrence of CD among Chinese children in South China. METHODS: Serum samples were collected from children and assessed for anti-tissue transglutaminase IgA antibodies (anti-tTG-IgA) and total IgA. Anti-tTG-IgA+ participants underwent human leukocyte antigen (HLA) DQ2/DQ8 determination. Samples with serum total IgA <0.05 g/L were also analyzed for anti-tTG-IgG, and for HLA-DQ2/DQ8 if the values were above borderline. Participants who were anti-tTG-IgA/IgG+ and HLA-DQ2+ and/or HLA-DQ8+ underwent small bowel biopsy. RESULTS: A total of 8794 children were enrolled, of whom 479 had chronic unexplained abdominal symptoms. Three (0.034%) children were anti-tTG-IgA+ and ten (0.114%) had serum total IgA <0.05 g/L, all of whom were anti-tTG-IgG-. The three positive children were all HLA-DQ2+ and/or HLA-DQ8+. Two underwent gastroscopy, and histopathology of small intestinal biopsy showed duodenal villous blunting in one and increased intraepithelial lymphocytes in the other, neither consistent with a diagnosis of CD. CONCLUSION: Our study showed a prevalence of CD autoimmunity of 0.034% and failed to identify any cases of CD, suggesting a low prevalence of CD among children in South China.

Predictive factors for glucocorticoid therapy in children with eosinophilic gastroenteritis. / å„¿ç«¥å—œé ¸æ€§ç²’ç»†èƒžæ€§èƒƒè‚ ç‚Žç³–çš®è´¨æ¿€ç´ æ²»ç–—çš„é¢„æµ‹å› ç´ åˆ†æž.

OBJECTIVES: To study the predictive factors for glucocorticoid therapy by analyzing the association between the clinical features and treatment regimens in children with eosinophilic gastroenteritis. METHODS: A retrospective analysis was performed on the medical data of 182 children with eosinophilic gastroenteritis who were admitted to Guangzhou Women and Children's Medical Center from January 2012 to December 2020. According to whether glucocorticoids were used, these children were divided into a glucocorticoid treatment group and a control group. The two groups were compared in terms of age, history of allergy, clinical symptoms, laboratory examination results, endoscopic findings, and pathological results of gastrointestinal mucosa. A multivariate logistic regression analysis was performed for the results with statistical significance. RESULTS: Of the 182 children, 36 (19.8%) received glucocorticoid therapy. The rates of hematochezia, anemia, and mucosal ulceration/luminal stenosis under endoscopy and the mucosal eosinophil infiltration count were significantly higher in the glucocorticoid treatment group than those in the control group (P<0.05). The serum albumin level in the glucocorticoid treatment group was significantly lower than that in the control group (P<0.05). The multivariate logistic regression analysis showed that mucosal ulceration/luminal stenosis under endoscopy (OR=10.830, 95%CI: 3.090-37.961, P<0.001) and the increased mucosal eosinophil infiltration count (OR=0.967, 95%CI: 0.941-0.993, P=0.015) were predictive factors for glucocorticoid therapy in children with eosinophil gastroenteritis. CONCLUSIONS: Mucosal ulceration/luminal stenosis under endoscopy or a significant increase in the mucosal eosinophil infiltration count based on pathology suggests that glucocorticoid therapy can be considered in children with eosinophil gastroenteritis.

Quality of Life among Community-Dwelling Middle-Aged and Older Adults: Function Matters More than Multimorbidity.

OBJECTIVES: Quality of life stands for the comprehensive assessment for health conditions and the central concerns in the seniors' care. The inter-relationship between health-related quality of life (HRQoL) and multimorbidity among community-dwelling healthy older adults remains uncertain. METHODS: Data of 1839 participants from the I-Lan Longitudinal Aging Study were excerpted for analysis. Functional status and HRQoL were measured by the Functional Autonomy Measurement System and the Chinese version of 12-item Short-Form Health Survey version 2. Poor HRQoL was defined as lowest quintile of physical and mental components summaries (PCS and MCS). Multivariable linear and logistic regression analysis were applied to explore associations between variables of interest. RESULTS: Adjusted for potential confounders, multivariable linear regression showed that multimorbidity and functional impairment were negatively associated with PCS (ß coefficients -1.8 vs. -8.4) and MCS (ß coefficients -1.9 vs. -4.8). Logistic regression affirmed similar associations that the odds of being poor HRQoL were 1.6 (95% CI 1.1-2.2) for multimorbidity, and 5.4 (95% CI 2.8-10.3) for functional impairment in PCS; 1.9 (95% CI 1.4-2.6) for multimorbidity and 6.0 (95%CI 3.2-11.5) for functional impairment in MCS. Adjusted for depressive symptoms and cognitive performance, functional impairment was significantly associated with poor physical component (OR:4.68, 95% CI: 0.35-19.34, p<0.001) and mental component in HRQoL (OR:2.4, 95% CI: 1.1-5.5, p=0.032), but the associations were insignificant in multimorbidity. CONCLUSIONS: Findings from the study strengthened the importance of functional performance on HRQoL among community-living middle-aged and older adults, which is essential in community health promotion activities and health service programs.

Crude glycerol impurities improve Rhizomucor miehei lipase production by Pichia pastoris.

Crude glycerol, a by-product of biodiesel production, was employed as the carbon source to produce lipase using Pichia pastoris. Under identical fermentation conditions, cell growth and lipase activity were improved using crude glycerol instead of pure glycerol. The impacts of crude glycerol impurities (methyl ester, grease, glycerol, methanol, and metal ions Na+, Ca2+, and Fe3+) on lipase production were investigated. Impurities accelerated P. pastoris entering the stationary phase. Na+, Ca2+, and grease in waste crude glycerol were the main factors influencing higher lipase activity. Through response surface optimization of Ca2+, Na+, and grease concentrations, lipase activity reached 1437 U/mL (15,977 U/mg), which was 2.5 times that of the control. This study highlights the economical and highly efficient valorization of crude glycerol, demonstrating its possible utilization as a carbon source to produce lipase by P. pastoris without pretreatment.

Value of Combination of Heart, Lung, and Diaphragm Ultrasound in Predicting Weaning Outcome of Mechanical Ventilation.

BACKGROUND Postextubation distress is detrimental to the prognosis of critically ill patients with successful spontaneous breathing trial. The known risk factors of failed weaning are associated with the heart, lungs, and diaphragm. The aim of this study was to explore the role of a combined model including indicators of heart, lung, and diaphragm ultrasound in predicting the weaning outcome. MATERIAL AND METHODS Patients' clinical data and ultrasonic features of heart, lungs, and diaphragm were recorded. Patients were included in either the failed weaning group (n=24) or the successful weaning group (n=81). The association of potential variables with the risk of weaning failure was determined using multivariate logistic regression analysis. The accuracy of potential indicators for predicting the weaning outcome were evaluated and a multiindicator combined model was established to improve the predictive accuracy. RESULTS Brain natriuretic peptide (odds ratio [OR]=1.120, P=0.004), left-atrial pressure (LAP) (OR=1.333, P=0.005), lung ultrasound score (LUS) (OR=1.736, P=0.001), and hemidiaphragm dysfunction (OR=3.942, P=0.014) were associated with an increased risk of weaning failure. However, all of these indicators could not accurately predict the weaning outcome independently (all areas under the curve [AUCs] <0.9). The combination of LAP, LUS, and hemidiaphragm dysfunction showed the highest AUC (AUC=0.919). CONCLUSIONS The combined model including LAP, LUS, and hemidiaphragm dysfunction were the most accurate method for the prediction.

Clinical manifestations and prognosis of SLE patients with positive anti-cardiolipin antibodies / 医学研究生学报

Objectives Anticardiolipin antibody (aCL) is an important component of antiphospholipid antibody (aPL) and a marker antibody of antiphospholipid syndrome (aPS). APL is positive in 20% to 40% of patients with systemic lupus erythematosus(SLE). This article investigated the clinical features and prognosis of SLE patients with aCL. Methods From January 1999 to December 2009, 495 cases of SLE patients detected aCL who were hospitalized for the first time in 26 hospitals in Jiangsu Province including Nanjing Drum Tower Hospital were divided into aCL-positive group and aCL-negative group according to the test results. The patients were followed up in survival status, and the demographic characteristics, affected organs, laboratory tests, treatment drugs, and prognosis were compared between two groups. Results 146 of the SLE patients in this group were positive for aCL. The proportion of women in aCL- positive group (96.6%) was significantly higher than that in aCL-negative group (90.8%), and the difference was statistically significant (P<0.05). The proportion of anemia (74.7% vs 61.3%), decreased C3(81.5% vs 71.1%), positive antinuclear antibody(97.2% vs 92.4%), and positive anti-dsDNA antibody (61.9% vs 49.6%) in aCL-positive group were significantly higher than those of aCL-negative group, and the difference was statistically significant (P<0.05). The aCL-positive group received a higher proportion of cyclophosphamide immunosuppressive therapy (39.5% vs 50.7%, P<0.05). At the end of follow-up, the mortality rate of aCL-positive group was 13.7%, and the mortality rate of aCL-negative group was 14.9% and there was no significant difference in mortality (P>0.05). Kaplan-Meier survival analysis showed that the 1-year, 5-year, and 10-year survival rates of aCL-positive group were 94.5%, 89.0%, and 82.9%, respectively, and there was no significant difference compared with aCL-negative group(P=0.776). The main causes of death in aCL-positive group were lupus encephalopathy (6 cases, 30.0%), renal failure (5 cases, 25.0%), heart failure (4 cases, 20.0%) and infection (3 cases, 15%). The main causes of death in aCL-negative group were infection (21 cases, 40.4%), lupus encephalopathy (11 cases, 21.2%) and heart failure (5 cases, 9.6%) and renal failure (4 cases, 7.7%). Conclusion SLE patients with aCL represent a high propotion in anemia, decreased C3, positive antinuclear antibody, positive anti-dsDNA antibody. There was no significant difference in disease activity and significant organ involvement between two groups. More SLE patients with aCL were treated with cyclophosphamide, and there was no significant difference in survival status between SLE patients with and without aCL during long-term follow-up.

Long-Term Outcomes of Caustic Esophageal Stricture with Endoscopic Balloon Dilatation in Chinese Children.

Caustic esophageal stricture (CES) in children still occurs frequently in developing countries. We aimed to evaluate the long-term outcomes of endoscopic balloon dilatation (EBD) in treating CES in children and the influencing factors associated with outcome. We retrospectively reviewed the data of all patients who had a diagnosis of CES and underwent EBD from August 1, 2005, to December 31, 2014. The primary outcome was EBD success, which was defined as the maintenance of dysphagia-free status for at least 12 months after the last EBD. The secondary outcome was to analyze influencing factors associated with EBD success. Forty-three patients were included for analysis (29 males; mean age at first dilatation 44 months with range 121 months). 26 (60.5%) patients had long segment (>2 cm) stricture. A total of 168 EBD procedures were performed. Twenty-six (60.5%) patients were considered EBD success. Seventeen (39.5%) patients failed EBD and required stent placement and/or surgery. Patients in the EBD success group had significantly shorter stricture segments when compared to the EBD failure group (t = 2.398, P = 0.018, OR = 3.206, 95% OR: 1.228-8.371). Seven (4.4%) esophageal perforations occurred in 6 patients after EBD. Stents were placed in 5 patients, and gastric tube esophagoplasty was performed in 14 patients. In conclusion, 26 (60.5%) of 43 children with CES had EBD success. Length of stricture was the main influencing factor associated with EBD treatment outcome.

[Protective effect of prostaglandin E1 against brain injury induced by hyperoxia in neonatal rats].

OBJECTIVE: To investigate the protective effect of prostaglandin E1 (PGE-1) against brain injury induced by hyperoxia in neonatal rats and observe the changes in the expression of glucose-regulated protein 78 (GRP78) and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), and to provide a theoretical basis for the clinical application of PGE-1 in the treatment of neonatal brain injury induced by hyperoxia. METHODS: Sixty neonatal Wistar rats were randomly divided into air control group, hyperoxic brain injury model group, and hyperoxic brain injury+PGE-1 group. All rats except those in the air control group were treated to establish a hyperoxic brain injury model. From the first day of modeling, the rats in the hyperoxia brain injury+PGE-1 group were intraperitoneally injected with PGE-1 2 µg/kg daily for 7 consecutive days, while the other two groups were treated with normal saline instead. The water content of brain tissue was measured; the pathological changes of brain tissue were evaluated by hematoxylin-eosin staining; the apoptosis of brain cells was assessed by nuclear staining combined with TUNEL staining; the protein expression of GRP78 and CHOP in brain tissue was measured by Western blot. RESULTS: The water content of brain tissue in the hyperoxic brain injury model group was significantly higher than that in the hyperoxic brain injury+PGE-1 group and air control group (P<0.05); the water content of brain tissue in the hyperoxic brain injury+PGE-1 group was significantly higher than that in the air control group (P<0.05). The pathological section of brain tissue showed inflammatory cell infiltration and mild cerebrovascular edema in the brain parenchyma in the hyperoxic brain injury model group; the periparenchymal inflammation and edema in the hyperoxic brain injury+PGE-1 group were milder than those in the hyperoxic brain injury model group. The apoptosis index of brain tissue in the hyperoxic brain injury model group was significantly higher than that in the hyperoxic brain injury+PGE-1 group and air control group (P<0.05); the apoptosis index of brain tissue in the hyperoxic brain injury+PGE-1 group was significantly higher than that in the air control group (P<0.05). The protein expression of GRP78 and CHOP in brain tissue was significantly higher in the hyperoxic brain injury model group than in the hyperoxic brain injury+PGE-1 group and air control group (P<0.05); the protein expression of GRP78 and CHOP was significantly higher in the hyperoxic brain injury+PGE-1 group than in the air control group (P<0.05). CONCLUSIONS: PGE-1 has a protective effect against hyperoxia-induced brain injury in neonatal rats, which may be related to the inhibition of cell apoptosis by down-regulating the expression of GRP78 and CHOP.

The implementation and evaluation of HIV symptom management guidelines: A preliminary study in China.

OBJECTIVE: The overarching objective of this study was to examine the effectiveness of HIV symptom management guidelines in China in reducing the incidence and severity of symptoms and improving patients' quality of life. METHODS: We conducted a controlled, pre- and post-implementation design in the HIV/AIDS inpatient unit in Shanghai. Patients recruited from November 2014 to February 2015 were in the intervention group and those from October 2013 to February 2014 were in the control group. There were 74 patients in each group. Participants in the intervention group received interventions based on the HIV symptom management guidelines. Overall symptom severity, depression, and quality of life were measured in two groups at baseline, week 4, and week 8. RESULTS: Totally 126 patients completed the research, 65 in the intervention group and 61 in the control group. The total symptom severity scores showed a statistically significant difference between groups across time (P < 0.05). It showed that frequencies of fatigue (36.9% vs. 44.3%), fever (6.2% vs. 11.5%), loss in weight (9.2% vs. 16.4%), mouth ulcers (12.3% vs. 16.4%), headaches (9.2% vs. 19.7%) and depression (F = 1.09, P > 0.05) in the intervention group were lower than those in the control group in week 8 without statistical significance. The multilevel growth mixture model indicated a greater increase in the total score of quality of life for the group treated according to the symptom management guidelines (P = 0.04). CONCLUSION: The evidence-based HIV symptom management guidelines can improve a patient's quality of life and relieve negative symptoms. The guidelines can be applied in a similar context to other HIV/AIDS units or clinics.

Bleeding Meckel's Diverticulum in Children: The Diagnostic Value of Double-Balloon Enteroscopy.

Background. Meckel's diverticulum (MD) is the most common congenital anomaly of the gastrointestinal tract. The purpose of this study was to evaluate the diagnostic value and safety of double-balloon enteroscopy (DBE) for bleeding MD in children. Methods. We included consecutive children who were highly suspected of MD between 2012 and 2013. All patients underwent Meckel's scan. DBE was performed for patient with negative Meckel's scan. An exploratory laparoscopy was performed in children with positive Meckel's scan or DBE. Results. 42 patients met the inclusion criteria. 40 patients were confirmed to have MD by exploratory laparoscopy. Meckel's scan was positive in 36 and negative in 6, with 34 as true positives and 2 as false positives. Six patients with negative Meckel's scan were found to have MD by retrograde DBE and had immediate operation. The distance from the diverticulum to the ileocecal valve was 40 to 60 cm. Ectopic gastric mucosa was present in all 6 patients (100%). After operation, patients were followed in clinic for 20 to 42 months and no evidence of GI bleeding or recurrent anemia was observed. Conclusions. Double-balloon enteroscopy can be a reliable diagnostic tool for bleeding Meckel's diverticulum in children with negative Meckel's scan.

Effects of vitrectomy combined with cataract surgery on the corneal endothelial cells in diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effects of vitrectomy combined with cataract surgery on the corneal endothelial cells in diabetic retinopathy.METHODS: A retrospective study was designed.160 patients(160 eyes) with diabetic retinopathy from Jan 2015 to Feb 2017 were divided into two groups according to cataract.74 patients(74 eyes) were operated on vitrectomy,and 86 patients(86 eyes) on vitrectomy combined with phacoemulsification cataract surgery and capsular bag implantation of foldable intraocular lens.To record the change of corneal endothelial cells density,average cellular area,coefficient of variation and percentage of hexagonal endothelial cell before and after treatment with Topcon corneal specular microscope.RESULTS: Before and after surgery,the results of corneal endothelial cells density,average cellular area,coefficient of variation and percentage of hexagonal endothelial cell in simple vitrectomy group were no significant difference(P>0.05);After treatment corneal endothelial cells density and percentage of hexagonal endothelial cell were changed with statistical difference as the same as average cellular area and coefficient of variation(P<0.05);There were significantly differences in corneal endothelial cells between two groups(P<0.05).CONCLUSION: It has certain influence on the corned endothelial cells when using vitrectomy combined with cataract surgery in diabetic retinopathy.For patients with indications,it should be paid attention to protecting the corneal endothelial cells.

Low switching voltage ZnO quantum dots doped polymer-dispersed liquid crystal film.

This paper investigates the effects of ZnO nanoparticles (NPs) on the switching voltages of polymer dispersed liquid crystal (PDLC) films. The threshold and driving electric fields of PDLC film doped with 2.44 wt% ZnO NPs were 0.13 and 0.31 V/µm, respectively, with a contrast ratio of 26. The results of field emission scanning electron microscopy show that the size of the droplets in doped PDLC films increases with the doping concentration. The development of ZnO-doped PDLC films with low driving voltages greatly broadens the applicability of these devices.

Cost-effectiveness analysis of an enteral nutrition protocol for children with common gastrointestinal diseases in China: good start but still a long way to go.

BACKGROUND: A standard nutrition screening and enteral nutrition (EN) protocol was implemented in January 2012 in a tertiary children's center in China. The aims of the present study were to evaluate the cost-effectiveness of a standard EN protocol in hospitalized patients. METHODS: A retrospective chart review was performed in the gastroenterology inpatient unit. We included all inpatient children requiring EN from January 1, 2010, to December 31, 2013, with common gastrointestinal (GI) diseases. Children from January 1, 2012, to December 31, 2013, served as the standard EN treatment group, and those from January 1, 2010, to December 31, 2011, were the control EN group. Pertinent patient information was collected. We also analyzed the length of hospital stay, cost of care, and in-hospital infection rates. RESULTS: The standard EN treatment group received more nasojejunal tube feedings. There was a tendency for the standard EN treatment group to receive more elemental and hydrolyzed protein formulas. Implementation of a standard EN protocol significantly reduced the time to initiate EN (32.38 ± 24.50 hours vs 18.76 ± 13.53 hours; P = .011) and the time to reach a targeted calorie goal (7.42 ± 3.98 days vs 5.06 ± 3.55 days; P = .023); length of hospital stay was shortened by 3.2 days after implementation of the standard EN protocol but did not reach statistical significance. However, the shortened length of hospital stay contributed to a significant reduction in the total cost of hospital care (13,164.12 ± 6722.95 Chinese yuan [CNY] vs 9814.96 ± 4592.91 CNY; P < .032). CONCLUSIONS: Implementation of a standard EN protocol resulted in early initiation of EN, shortened length of stay, and significantly reduced total cost of care in hospitalized children with common GI diseases.

Co-expression of the Arabidopsis SOS genes enhances salt tolerance in transgenic tall fescue (Festuca arundinacea Schreb.).

Crop productivity is greatly affected by soil salinity; therefore, improvement in salinity tolerance of crops is a major goal in salt-tolerant breeding. The Salt Overly Sensitive (SOS) signal-transduction pathway plays a key role in ion homeostasis and salt tolerance in plants. Here, we report that overexpression of Arabidopsis thaliana SOS1+SOS2+SOS3 genes enhanced salt tolerance in tall fescue. The transgenic plants displayed superior growth and accumulated less Na+ and more K+ in roots after 350 mM NaCl treatment. Moreover, Na+ enflux, K+ influx, and Ca2+ influx were higher in the transgenic plants than in the wild-type plants. The activities of the enzyme superoxide dismutase, peroxidase, catalase, and proline content in the transgenic plants were significantly increased; however, the malondialdehyde content decreased in transgenic plants compared to the controls. These results suggested that co-expression of A. thaliana SOS1+SOS2+SOS3 genes enhanced the salt tolerance in transgenic tall fescue.

[Role of BCG-depleted immunodominant antigens derived from M. tuberculosis in serological test for tuberculosis].

OBJECTIVE: To explore the roles of BCG-depleted immunodominant antigens derived from M. tuberculosis in serological tests for tuberculosis (TB). METHODS: Four different combinations of current mainstream antigens used for serological diagnosis of TB were selected: Reagent A [Mycobacterium TB immunoglobulin G (IgG) antibody assay kit]; Reagent B (Mycobacterium TB detection kit); Reagent C (M. tuberculosis-specific antibody detection kit); Reagent D [Active TB antibody detection enzyme-linked immunosorbent assay (ELISA) system]. Immunological methods of Western blot, colloidal gold and ELISA were developed to test the antibodies in 109 patients with active tuberculosis (TB) and 97 healthy populations. They were divided into purified protein derivative of tuberculin (PPD) positive and negative groups. Bayesian statistical analysis was used to analyze the influences of variable combinations of different antigens on the detection accuracy of TB. RESULTS: For Reagent A, B, C, D, the detection rates of IgG antibodies in the patients with active TB were 80.0%, 66.7%, 80.7%, 56.0% versus 23.9%, 8.9%, 6.6% and 1.0% respectively in healthy populations. The TB antibody detection rates in four TB patient populations were all higher than that in healthy populations (χ(2) = 47.53, 51.59, 90.48, 69.68, all P < 0.01). The TB antibody detection rates of Reagents A and B increased with the intensity of positive reaction to PPD in healthy populations (χ(2) = 2.124, 2.220, all P < 0.05) while those of Reagents C, D in healthy populations were irrelevant to PPD reaction. (χ(2) = 0.122, 0.479, all P > 0.05). Reagent D has the highest accuracy. The immunoglobulin M (IgM) antibody detection rate of Reagent D was only 2.1% in the patients with active TB. CONCLUSIONS: The detecting sensitivity of TB IgG antibodies is associated with antigen selection. And it is also positively correlated with the number of combined antigens. High-sensitivity detection is often accompanied by a loss of specificity. With the BCG-depleted antigens derived from M. tuberculosis, the specificity of serological test for TB may significantly improve.

[Distribution characters of sulfur in flue-cured tobacco leaf and available sulfur in soil in hunan tobacco-growing areas].

Through field survey and laboratory analysis, this paper studied the distribution characters and interrelationships of sulfur in flue-cured tobacco leaf and available sulfur in soil in Hunan tobacco-growing areas of China. The results indicated that in Hunan tobacco-growing areas, the sulfur content in flue-cured tobacco leaf was relatively high as compared with other tobacco-growing areas in China, which ranged from 0.34% to 1.49%, with the mean of (0.81 +/- 0.26)%. 39.29% of the leaf samples had a sulfur content of < 0.70%, and the sulfur content in different grades of flue-cured tobacco leaves was B2F > C3F > X2F. The available sulfur content in soil was rich, which ranged from 2.20 to 217.60 mg x kg(-1), with the mean of (37.16 +/- 27.59) mg x kg(-1). Among the soil samples collected, 22.58% of them were considered as lack of sulfur ( < or =16.0 mg x kg(-1)), 26.08% had an available sulfur content exceeding 50.0 mg x kg(-1), and 51.34% could satisfy the sulfur demand of high quality tobacco. The available sulfur content in different types of soil was in the order of duck feces mud > yellow mud field > red yellow mud > blue mud field > sand mud field > yellow ash soil > yellow soil. There was a very significant positive correlation between the contents of sulfur in flue-cured tobacco leaf and available sulfur in soil (r = 0.469, P < 0.01).