[The method of determination for 2, 3-Butanedione in the air of workplace by high performance liquid chromatography with derivatization].

Objective: To establish a method for the determination of 2, 3-Butanedione (BUT) in the air of workplace, which including the process of collection by absorption in phosphoric acid aqueous solution and the process of analysis and detection by high performance liquid chromatography with derivatization. Methods: In October 2022, a porous glass plate absorption tube containing 10 ml of 0.01% phosphoric acid solution was used to collect BUT in the air of the workplace at a flow rate of 0.2 L/min. The absorption solution was derived by 2, 4-dinitrophenylhydrazine for 75 min and separated on a SB-C18 column (250 mm×4.6 mm, 5 µm) . At the column temperature of 30 ℃, the mixture of acetonitrile-water (V∶V, 1∶1) was eluted at the flow rate of 1.0 ml/min. It was detected by UV detector (λ=365 nm) , qualitatived by retention time and quantitatived by external standard. Results: It showed that BUT in phosphoric acid aqueous solution could be stored for at least 7 d at 4 ℃. There was a linear relationship within the determination range of 0.05-6.00 µg/ml, the linear regression equation was y=89.610x+0.133, r=0.9999. The sampling absorption efficiencies were 98.33%-100.00%, the detection limit of the method was 0.005 µg/ml, the minimum detection concentration was 0.016 mg/m(3) (based on V(0)=3.0 L) . The recovery rates were 95.96%-102.44%, the intra batch precision were 4.36%-7.78%, and the inter batch precision were 4.96%-6.06%. Conclusion: The method has the advantages of simple operation, high sensitivity and good accuracy. It can prevent the loss and degradation of BUT. It can be used for the determination of BUT in the air of workplace.

Secondary ear reconstruction based on the Nagata method after unsatisfactory microtia surgery outcomes.

BACKGROUND: Follow-up studies on auricular reconstruction procedures have reported postoperative complications; some of which can only be reversed with revision surgery. This study aims to provide a feasible surgical strategy based on the Nagata method for patients requiring secondary revision and verify mid-term aesthetic outcomes. METHODS: Secondary auricular reconstructions based on the Nagata method were performed on seven patients seeking secondary revision between 2017 and 2021. Scores of a five-point Likert scale and artificial intelligence ratings based on convolutional nerve networks were used as outcome measures. RESULTS: Five patients underwent complete two-stage ear reconstruction, and the other two patients underwent the first-stage microtia procedure only. Few complications were observed, except in Case 4; this patient required an additional minor surgery after frame exposure 6 weeks after the first-stage procedure. All revised ears showed clear anatomical structures, and all patients were satisfied with the aesthetic results. Statistical analysis showed a significant increase in postoperative versus preoperative scores by convolutional neural network models (p < 0.05). Cases 5 and 6, which involved projection surgeries only, had decreased artificial intelligence appearance scores postoperatively. CONCLUSION: After adequate preoperative evaluation, secondary auricle reconstruction based on the Nagata method can achieve reliable aesthetic outcomes with few complications. CLINICAL TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov ID: NCT05604456.

[Meta-analysis on the contents of trace elements in workers with occupational exposure to lead].

Objective: To quantitatively evaluate the content differences of trace elements in workers with occupational exposure to lead. Methods: In January 2021, relevant literatures on the contents of trace elements in workers with occupational exposure to lead published from 1990 to 2020 were searched through CNKI, Wanfang, VIP, PubMed, web of science and Embase. Screened and extracted the literatures, and evaluated the quality of the included literatures with Newcastle Ottawa Scale. Meta analysis was performed with Review Manager 5.3 software, and standardized mean difference (SMD) and its 95% confidence interval were used as effect indicators. Results: A total of 20 literatures were included, and the quality scores were 5-7. The results of Meta-analysis showed that compared with the control group, the contents of blood zinc (SMD=-1.01, 95%CI: -1.53, -0.49) , hair zinc (SMD=-0.17, 95%CI: -0.33, -0.01) , hair copper (SMD=-0.50, 95%CI: -1.01, 0) , hair iron (SMD=-3.91, 95%CI: -5.80, -2.03) and hair manganese (SMD=-1.09, 95%CI: -2.02, -0.15) in occupational lead exposure group were significantly lower (P<0.05) . Compared with the control group, the content of cobalt in hair of occupational lead exposure group (SMD=1.41, 95%CI: 0.72, 2.10) was higher, and the difference was statistically significant (P<0.05) . There was no significant difference in the contents of blood chromium, blood copper, blood iron, blood manganese, blood selenium and hair nickel between the two groups (P>0.05) . Conclusion: Workers with occupational exposure to lead have abnormal trace elements.

[Determination of the butanone in urine by gas chromatography with precolumn derivation].

Objective: To establish a method for determination of the butanone in urine by gas chromatography (GC) with pre-column derivation. Methods: For detecting of butanone in urine, potassium iodide and potassium dichromate were added into urine under acidic condition, sample derivatization was undertaken in 50 ℃ water bath for 60 min and the iodine butanone was extracted with n-hexane. After the sodium thiosulfate solution was used to remove excess iodine, urine samples were centrifuged at 10000 r/min for 5 min, then the supernatant was analyzed using temperature rising programming with the Agilent Hp-5 column (30 m×0.32 mm, 0.25 µm) and electron capture detector (ECD) as the detector. The detector temperature was 300 ℃, the inlet temperature was 200 ℃, and the carrier gas was nitrogen. Results: For detecting of butanone in urine, potassium iodide and potassium dichromate were added for derivatization under the acidic condition. After extraction and centrifugation, the supernatant directly put through column and detected by ECD. In present study, the sample pretreatment condition was optimized, the relative standard deviations of intra-day and inner-day, the spiked samples and its recovery were evaluated for analyzing the accuracy of the proposed method. Conclusion: This method has proved to be simple, efficient and highly sensitivity, it can be utilized for butanone detection in occupational population.

[Applications of the Fe(3)O(4) nanocomposite modified by Humic Acid in determination of S-phenylmercapturic acid in urine by dispersive solid-phase extraction and HPLC].

Objective: To establish a method for determination the S-phenylmercapturic acid in urine by dispersive solid-phase extraction using Humic Acid/Fe(3)O(4) magnetic nanocomposite as adsorbent. Methods: The 5 ml of urine samples were adjusted to pH 1.0 and extracted by Fe3O4@HA. Then the analytes were separated on EC-C(18) capillary column and detected by HPLC-VWD. The S-phenylmercapturic acid was characterized by the retention time and quantified by peak area and external standard method. Results: The standard curves of SPMA showed significant linearity between 0.04~1.00 mg/L (r=0.999 7) . The average recovery was 94.2%~102.4%. The intra-day and inter-day precisions (RSD) were 2.9~6.7% (n=6) and 3.1~7.5% (n=6) respectively. The detect limit of SPMA was 0.012 g/L (S/N=3) . Conclusion: This method is simple, rapid, sensitive and accurate. It is applicable for determination of SPMA in the urine of works who were exposed to benzene.

[Simultaneous determination of trichloroethylene and trichloroethanol in blood by liquid-liquid extraction-gas chromatography].

Objective: To establish a method for determing the trichloroethylene(TCE)and trichloroethanol(TCOH)in blood samples by liquid-liquid extraction-gas chromatography with electron capture detector. Methods: With this method,ether was used as extraction solvent and trichloromethane was used as an internal standard. The whole blood sample was extracted with ether, and dehydrated by anhydrous sodium sulfate. Then the analytes were separated on HP-5 capillary column(30m×0.32mm×0.15µm)and detected byECD.The retention time was for qualitative analysis and the internal standard was for quantitation. Results: The standard curves of TCE and TCOH showed significant linearity between 95.5µg/L-7640.0µg/L(r=0.9997)and 19.0µg/L-1520.0µg/L(r=0.9992). The average recovery was 95.5%-103.6%.The intra-day and inter-day precisions(RSD)were 2.5%-6.8%(n=6)and 1.6%-4.3%(n=6) respectively. The detect limit of TCE and TCOH were 2.10 µg/L and 0.56µg/L(S/N=3)respectively.The blood can be kept 7 days at-20℃ refrigerator without significantly loss. Conclusion: This method is proved to be simple,practical and highly sensitive. It can satisfy the request for the determination of blood samples of humans exposed to TCE.

Follow-up observational study of "bi-ring method" breast surgery for treating hypermastia and mastoptosis.

PURPOSE: This study investigated the efficacy and patient satisfaction of "bi-ring method" breast surgery in 46 patients with hypermastia and/or mastoptosis. MATERIALS AND METHODS: A questionnaire survey, objective data measurements, visual analysis system survey, and various scoring scales were used to qualitatively and quantitatively assess the patients' indicators before and after surgery. RESULTS: Statistical analysis showed the following: symptoms and signs in patients with macromastia improved significantly; all patients' breast shapes improved significantly and became more symmetrical and durable; all patients had minor hidden scars; the nipples and areolas had good feeling postoperatively, and there were relatively few mild complications. CONCLUSIONS: The patients' overall satisfaction was high, indicating that the "bi-ring method" of breast plastic surgery could not only improve the breast shape and boast concealed scars but could significantly improve the patients' signs and symptoms of hypermastia, but the nipples and areolas had good postoperative feeling and there were few complications. Thus, this is a reasonable surgical approach that is worthy of promotion.

Multilocus variable-number tandem-repeat analysis of Neisseria meningitidis serogroup C in China.

This study characterized Neisseria meningitidis serogroup C strains in China in order to establish their genetic relatedness and describe the use of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) to provide useful epidemiological information. A total of 215 N. meningitidis serogroup C strains, obtained from 2003 to 2012 in China, were characterized by MLVA with different published schemes as well as multilocus sequence typing. (i) Based on the MLVA scheme with a combination of five highly variable loci, 203 genotypes were identified; this level of discrimination supports its use for resolving closely related isolates. (ii) Based on a combination of ten low variable loci, clear phylogenetic relationships were established within sequence type complexes. In addition, there was evidence of microevolution of VNTR loci over the decade as strain lineages spread from Anhui to other provinces, the more distant the provinces from Anhui, the higher the genetic variation.

A universal fluorescence sensing strategy based on biocompatible graphene quantum dots and graphene oxide for the detection of DNA.

A novel and efficient fluorescence sensing platform based on biocompatible graphene quantum dots and graphene oxide was established. It showed high selectivity and sensitivity for DNA detection.

The novel HLA-B*48:19 allele, identified by sequence-based typing in a Chinese individual.

HLA-B*48:19 differs from HLA-B*48:01:01 exon 3 2 nt at position 195 and 196 (C→T and T→G).

Characterization of a novel allele, HLA-B*15:139.

The novel allele HLA-B*15:139 was closest to HLA-B*15:02,*15:18, with a single-nucleotide mismatch in exon 2.

The novel allele HLA-A*02:145 differs from HLA-A*02:01:01 by a single amino acid exchange at position 153 from alanine to valine.

HLA-A*02:145 differs from HLA-A*02:02:01:01 by the amino acid exchange at position 153 Ala changes to Val.

A novel HLA-A*02 allele, HLA-A*02:129.

HLA-A*02:129 differs from HLA-A*02:87 exon 2 at nt 25, nt 29, nt 167 T, nt 184 and nt 192.

The novel allele HLA-DQB1*06:01:04 differs from HLA-DQB1*06:01:01 by a single synonymous nucleotide exchange.

HLA-DQB1*06:01:04 differs from HLA-DQB1*06:01:01 by the nucleotide exchange at position 156 (G >C) without an amino exchange.

A novel HLA-C*15 allele, HLA-C*15:02:04.

HLA-C*15:02:04 differs from HLA-C*15:02:01 by the nucleotide exchange at position 143.

A novel HLA allele, HLA-B*39:46, identified by sequence-based typing in a Chinese volunteer bone marrow donor.

The novel HLA-B*39:46 differs from HLA-B*39:01:01:01 by one base substitution at position 27(C>G) of exon 4.

Sequence-based typing identified a new HLA-B*40 allele, HLA-B*40:124:02.

The sequence of a novel allele, HLA-B*40:124:02, differs from HLA-B*40:42 by three-nucleotide exchanges in exon 3.

Identification of a novel HLA-A allele HLA-A*02:227N.

The HLA-A*02:227N allele differs from the closest matching allele A*02:01:01:01 by one nucleotide substitution in exon 3 at nt 610 (C→T).

Identification of a novel HLA-B allele HLA-B*13:20 in a Chinese individual.

The HLA-B*13:20 allele differs from the closest matching allele B*13:01:01 by one nucleotide substitution in exon 3 at nt 527 (T→A).

Is China facing an obesity epidemic and the consequences? The trends in obesity and chronic disease in China.

BACKGROUND: Over the past two decades, China has enjoyed impressive economic development, and her citizens have experienced many remarked changes in their lifestyle. These changes are often associated with an increase in obesity and chronic disease. METHODS: In this meta-analysis, based on nationally representative data, we studied the current prevalence of obesity and the trends in obesity, mortality and morbidity in China. RESULTS: Between 1992 and 2002, the prevalence of overweight and obesity increased in all gender and age groups and in all geographic areas. Using the World Health Organization body mass index cut points, the combined prevalence of overweight and obesity increased from 14.6 to 21.8%. The Chinese obesity standard shows an increase from 20.0 to 29.9%. The annual increase rate was highest in men aged 18-44 years and women aged 45-59 years (approximately 1.6 and 1.0% points, respectively). In general, male subjects, urban residents, and high-income groups had a greater increase. With the increase in overweight and obesity, obesity-, and diet-related chronic diseases (e.g., hypertension, cardiovascular disease (CVD), and type 2 diabetes) also increased over the past decade and became a more important preventable cause of death. Hypertension increased from 14.4% in 1991 to 18.8% in 2002 in adults; in older adults aged 35-74 years, it increased from 19.7 to 28.6%. Between 1993 and 2003, the prevalence of CVD increased from 31.4 to 50.0%; diabetes increased from 1.9 to 5.6%. During 1990-2003, although total mortality rate (per 100 000) decreased, overall the mortality rate and contribution (as percentages) to total death of obesity-related chronic disease increased, in particular, in rural areas. Mortality rate (per 100 000) of CVD increased from 128 to 145 and its contribution to total death, 27 to 32%, in rural areas; the figures decreased slightly in urban areas. The mortality rate of 'nutrition, endocrinology and metabolism-related disease' (NEMD) increased in both rural and urban areas between 1990 and 2000, 8.0 to 10.6 and 4.9 to 5.3, respectively. The current prevalence of hypertension, dyslipidaemia, metabolic syndrome, and diabetes among Chinese adults is approximately 20, 20, 15, and 3%, respectively. CONCLUSION: The prevalence of overweight and obesity and obesity-related chronic diseases have increased in China in the past decade. Our findings provide useful information for the projection of future trends and the formulation of national strategies and programmes that can address the challenges of the growing obesity and chronic disease epidemic.