The usage of pesticides can enhance the production of crops,but their overuses may be hazardous to both people health and the environment.Thus,it is of great significance to develop effective methods to detect pesticides.Metal nanoclusters(MNCs)have become increasingly popular in analytical sensing areas because of their miniscule size,high stability,ease of manufacturing and good biocompatibility.They have exhibited great potential in the field of pesticides detection.In this paper,the detection methods of pesticides by using MNCs and their development in detection of organophosphorus pesticides,organic nitrogen pesticides,organochlorine pesticides and other types of pesticides were reviewed.Finally,the development prospects were discussed.

The patient,a 42-year-old male,with a history of hepatitis B and membranous nephropathy,had inter-mittent fever and chills 12 days before admission.In the first 2 days after admission,the patient's condition aggra-vated with redness,swelling and pain in the left scrotum and perineum.Immediate surgical debridement was per-formed.The patient had a persistent low fever,with blood and pus cultures showing Candida albicans positive,thus was diagnosed fungal necrotizing fasciitis and pyomyositis.The patient was treated with echinocandins mica-fungin(150 mg,qd)for antifungal infection,and was given encroaching dressing change,hyperbaric oxygen thera-py,nutritional support,etc.Two months after surgery,the patient's condition improved and he was discharged.The early clinical symptoms of necrotizing fasciitis and pyomyositis caused by Streptococcus spp.infection lack spe-cificity,thus are prone to be delayed.For patients with concomitant immune diseases,attention should be paid to the prevention and early treatment of complex infection.The appropriate selection of empirical antifungal agents at the early stage has clinical significance.

AIM: To evaluate the clinical efficacy of wearing base curve aspheric orthokeratology(OK)lens in the control of myopia.METHODS: A prospective study was conducted. A total of 94 cases(94 eyes)of myopia aged 8～13 years old who were fitted with orthokeratology(OK)lens in our hospital from January 2020 to July 2021 were selected(for patients who received OK lens in one eye, the eye is selected as the observation eye, and for patients who receive OK lens in both eyes, the right eye is used as the observation eye). Patients were divided into two groups according to the design of the OK lens, with 46 cases wearing base curve aspheric OK lens in study group and 48 cases wearing base curve spheric OK lens in control group. The study group and the control group were further divided into low myopia group(-3.00D< SE ≤-0.75D)and moderate myopia group(-6.00D< SE ≤-3.00D)according to the baseline spherical equivalent(SE), with 52 cases(52 eyes)in the low myopia group and 42 cases(42 eyes)in the moderate myopia group. Uncorrected visual acuity(UCVA)was evaluated at 1d, 1wk, 1, 3, 6 and 9mo after wearing lenses, and axial length were measured at 6mo and 1a after wearing lenses respectively.RESULTS: All patients completed follow-up, and there was no significant differences in UCVA(LogMAR)between the study group(-0.12±0.08)and the control group(-0.17±0.07)after wearing the OK lens for 1mo(P>0.05); the mean axial length elongation between the two groups had no significant differences after wearing lenses for 6mo and 1a(all P>0.05). In the low myopia group, the axial length elongation of the study group was 0.19±0.17mm after wearing OK lens for 1a, which was significantly lower than that of the control group(0.31±0.18mm; P<0.05); while in the moderate myopia group, the axial length elongation was 0.22±0.18mm, and it had no significant differences with that in the control group(0.19±0.12mm; P>0.05). There was no significant differences in axial length elongation between the low myopia group and the moderate myopia group in study group after wearing lenses for 6mo and 1a(P>0.05), while there was differences in axial length elongation between low myopia group and moderate myopia group in the control group after wearing lenses for 6mo(0.15±0.13 vs. 0.05±0.12mm)and 1a(0.31±0.18 vs. 0.19±0.12mm; all P<0.05).CONCLUSION: Wearing base curve aspheric OK lens can effectively improve the UCVA and control the elongation of axial length. For patients with low myopia, base curve aspheric OK lens had a better efficacy in controlling the elongation of axial length than the spheric OK lens.

Objective: To evaluate the household secondary attack rates of the SARS-CoV-2 Delta variant and the associated factors. Methods: A COVID-19 outbreak caused by the Delta variant occurred in Nanjing in July 2021. A total of 235 cases with current addresses in Nanjing were reported from 171 households. The subjects in this study were selected from household close contact(s) of infected cases. The information on household index cases and their contacts were collected, and the household secondary attack rate (HSAR) and the risk factors were analyzed by the multi-factor logistic regression model. Results: A total of 234 cases of household close contacts and 64 household secondary cases were reported from 103 households, and the HSAR was 27.4% (64/234, 95%CI:22.0% to 33.4%). The proportions of household size for 2 to 3, 4 to 5, and 6 to 9 were 64.1% (66), 26.2% (27) and 9.7% (10), respectively. A total of 35 cases of household cluster outbreaks were reported (35/103, 34.0%). The number of the first case in the household (FCH) was 103 and males accounted for 27.2% (28 cases), with the median age (Q₁, Q₃) of 49 (9, 56). The number of household close contacts was 234 and males accounted for 59.0% (138 cases), with the median age (Q₁, Q₃) of 42 (20, 55) and the median exposure period (Q₁, Q₃) of 3 (1, 3) days. The multi-factor logistic regression model showed that the higher HSAR was observed in the FCH with the features of airport staff (OR=2.913, 95%CI:1.469-5.774), detection from home quarantine screening (OR=6.795, 95%CI:1.761-26.219) and detection from mass screening (OR=4.239, 95%CI:1.098-16.368). Meanwhile, higher HSAR was observed in cases with longer household exposure (OR=1.221, 95%CI:1.040-1.432), non-vaccination (OR=2.963, 95%CI:1.288-6.813) and incomplete vaccinations (OR=2.842, 95%CI:0.925-8.731). Conclusion: The generation interval of the Delta variant is shortened, and the ability of transmission within the household is enhanced. In the outbreak in Nanjing, the associated factors of HSAR are occupation, detection route, vaccination and exposure period.
Male ; Humans ; SARS-CoV-2 ; COVID-19/epidemiology* ; Incidence ; Family Characteristics

OBJECTIVES: To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China. METHODS: A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups. RESULTS: Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05). CONCLUSIONS There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.
Bronchopulmonary Dysplasia/epidemiology* ; Female ; Gestational Age ; Humans ; Infant ; Infant, Extremely Premature ; Infant, Newborn ; Pregnancy ; Respiratory Distress Syndrome, Newborn/epidemiology* ; Retrospective Studies ; Treatment Outcome

ObjectiveIn the past， many studies have reported the mode of colorectal cancer（CRC） metastasis， but there is still a lack of research based on long-term follow-up and death as the end point to summarize the location， mode and related survival data of CRC metastasis. MethodsThe data of 373 dead patients with colorectal cancer in the Sixth Affiliated Hospital of Sun Yat-sen University were reviewed， and the location， mode， incidence and survival data of tumor metastasis were statistically analyzed. Results334 patients （89.5%） died of tumor related death. The liver metastasis rate was 51.5%， the lung metastasis rate was 40.4%， and the peritoneal metastasis rate was 55.7%. The number of patients with liver， lung or peritoneal metastasis only was 27 （8%）， 21 （6.3%） and 63 （18.9%） respectively. The prognosis of patients with simple lung metastasis was better （P<0.01）. There were 66 patients （19.7%） with simultaneous metastasis of liver， lung and peritoneum， and the prognosis was the worst （P<0.01）. ConclusionNot all dead colorectal cancer patients have simultaneous metastasis of liver， lung and peritoneum. There are differences in the location and mode of metastasis in different patients， which is related to survival.

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 μg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 μg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 μg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.
Air Pollutants, Occupational/analysis* ; Chromatography, Gas/methods* ; Nitriles ; Workplace

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent ; Brain Abscess ; Child ; Child, Preschool ; Escherichia coli ; Female ; Humans ; Hydrocephalus ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial/epidemiology* ; Retrospective Studies ; Streptococcus agalactiae ; Streptococcus pneumoniae ; Subdural Effusion ; beta-Lactamases

Objective: To establish a method for the determination of acetylacetone in the air of workplace by gas chromatography. Methods: In August 2020, acetylacetone in the air of workplace was collected by silica gel tube, eluted with methanol, separated and detected by gas chromatography with flame ionization detector. The detection limit and precision of the method were also analyzed. Results: The linear range of acetylacetone was 1.95-1950.60 μg/ml with the regression equation of y=0.815x-3.667, and the correlation coefficient was 0.99993. The limit of detection of the method was 0.18 μg/ml and the minimum detection concentration was 0.12 mg/m(3) (collected sample volume was 1.50 L). The within-run precisions were 1.08%-4.11% and the between-run precisions were 1.98%-2.80%. The desorption rates were 99.68%-100.45%. The sealed samples could be kept at least 15 days at room temperature without significant loss. Conclusion: The solvent desorption-gas chromatography method for the determination of acetylacetone has good precision, high sensitivity and simple operation, and is suitable for the determination of acetylacetone in the air of the workplace.
Solvents ; Air Pollutants, Occupational/analysis* ; Chromatography, Gas/methods* ; Workplace

OBJECTIVE: To establish a method for simultaneous determination of 15 kinds of vapor state organic acids in workplace air by solvent desorption-gas chromatography.METHODS: A total 15 kinds of vapor state organic acids such as acetic acid, propanoic acid, butyric acid and pentanoic acid in the air of workplace were collected by silica gel, eluted with acetone, separated by DB-FFAP capillary chromatograph column, and detected by gas chromatography with flame ionization detection. RESULTS: There was a good linear relationship in the selected range of 15 kinds of organic acids. The coefficient correlation was 0.999 97-0.999 98. The limit of detection of this method was 0.04-0.29 mg/L, and the minimum detection concentration was 0.03-0.19 mg/m~(3 )(collected sample volume was 1.50 L). The average desorption efficiency was 92.9%-98.5%. The within-run and between-run relative standard deviation was 0.3%-1.6% and 1.5%-3.0%, respectively. The samples could be kept for at least 15 days at room temperature. CONCLUSION: The method is simple for operation, with high sensitivity, and good precision, which is suitable for simultaneous determination of 15 kinds of vapor state organic acids in the air of workplace and sites of emergency accident.