[Analysis of symptoms and influencing factors of low back work-related musculoskeletal disorders among workers in a container manufacturing factory].

Objective: To investigate the occurrence of low back work-related musculoskeletal disorders (WMSDs) among workers in a container manufacturing factory, and to explore the influencing factors. Methods: In June 2022, 952 workers from a container factory were selected as the research objects by cluster random sampling. Through questionnaire survey, the incidence of low back WMSDs symptoms among workers in the past one year was collected, and the influencing factors of low back WMSDs were analyzed by logistic regression. Results: The incidence rate of low back WMSDs was 46.7% (445/952). The factors with higher exposure at work were frequent slight bending (77.0%, 733/952), frequent overtime (74.1%, 705/952), and the need to turn around while working (62.3%, 593/952). Multivariate logistic regression analysis showed that age over 40 years old, smoking, drinking, often bending over slightly, sitting for a long time, maintaining a large bending posture for a long time, often working overtime, limited operating space, and there was always a need to complete conflicting things in the container manufacturing factory workers were the risks of increasing the low back WMSDs (OR=1.68, 1.96, 2.47, 1.49, 1.84, 2.11, 1.90, 1.82, 2.00, P<0.05). Standing at work, always friendly colleagues, and always supportive and helpful leaders were protective factors for low back WMSDs (OR=0.60, 0.32, 0.40, P<0.05) . Conclusion: The incidence of low back WMSDs symptoms in container manufacturing workers is high, and work-related factors such as frequent slight bending, long time holding large bending posture and limited operating space are the focus of ergonomic intervention in container manufacturing enterprises.

Crystallization mechanism of the Pt50Au50 alloy with grain boundary segregation during the solidification process.

The crystalline mechanism of the Pt50Au50 alloy with grain boundary (GB) segregation during the rapid solidification process is investigated using molecular dynamics simulations. The cluster evolution and phase transformation processes during the GB segregation are analyzed by means of the energy temperature (E-T) curve, the pair distribution function (g(r)) curves, common neighborhood analysis (CNA), cluster-type index method (CTIM) and three-dimensional visualizing analyses. It is found that the GB segregation phenomenon of the Pt50Au50 alloy comes from various solidification temperatures of Pt- and Au-centered clusters. Four critical temperatures T1 (1153 K), T2 (1073 K), T3 (853 K) and T4 (753 K) are discovered during the liquid-solid transition, corresponding to the supercooled liquid, Pt-centered atom nucleation, Pt-centered cluster growth, Au-centered atom nucleation and grain growth process, respectively, which is observably different to the solidification process of other alloys. The Pt atoms begin to gather together in the high-temperature liquid before the liquid-solid transition. It is also found that the CTIM proposed by us would provide an effective tool to investigate the GB segregation process.

[Neck musculoskeletal disorders and their influence factors among welders in an automobile factory].

Objective: To explore the prevalence and risk factors of neck musculoskeletal diseases (MSDs) of welders among an automobile factory. Methods: In June 2019, a cluster random sampling method was used to select 677 electric welders from an automobile manufacturing plant in Shiyan City as the survey objects, and a questionnaire survey was conducted using the "Musculoskeletal Disorders Questionnaire" to analyze the prevalence and influencing factors of neck MSDs, and used logistic regression to analyze the relationship between the influencing factors and the prevalence of cervical MSDs. Results: The prevalence rate of MSDs in neck of welders was 54.8% (371/677) . The exposure rate of occupational factors, from high to low, were neckin a bent formord porsure was 71.6% (486/677) , repetitive head movements was 55.1% (373/677) , working in uncomfortable postures was 48.7% (330/677) and neck twisted was 46.8% (317/677) respectively. Sex, age, educational level, length of service, smoking, neck tilt, neck twist, working in uncomfortable posture and head repetitive movements were the risk factors of neck MSDs (P<0.05) . Multiple logistic regression analysis showed that, the main influencing factors of neck MSDs were sex, education level, age, length of service, smoking, neck tilt, working in uncomfortable posture (OR = 2.11, 2.03, 1.83, 1.21, 1.78, 1.90, 1.58, 95%CI: 1.28~3.48、1.47~2.81、1.33~2.52、1.03~1.41、1.22~2.60、1.28~2.83、1.11~2.27, P<0.05) , rest had protective effect on neck MSDs (OR= 0.38, 95%CI: 0.17~0.88, P<0.05) . Conclusion: Welders in automobile factory was highly exposed to occupational risk factors for neck MSDs. Occupational risk factors such as neck in a bent forward posture, working in an uncomfortable posture, prolonged siting, repetitive head movement should be the focus of intervention.

[Effects of individual factors and labor organization on neck pain in auto assembler].

Objective: To investigate the influence of individual factors and labor organization on the prevalence of neck pain (hereinafter referred to as neck pain) in automotive assemblers, and to provide a basis for enterprises to optimize neck pain interventions. Methods: A cluster random sampling method was taken in January 2021, at an automobile manufacturing plant in Shiyan, 656 assemblers with ≥1.0 years of service were selected, the "Musculoskeletal Disorder Questionnaire" was used to investigate the incidence and influencing factors of neck pain. Pearson χ(2) test or trend χ(2) test was used to compare the data rates. The influencing factors of neck pain were analyzed by multivariate logistic regression. Results: The prevalence rate of neck pain (hereinafter referred to as the prevalence rate of neck pain) of automobile assemblers within one year was 53.94% (342/634) . The prevalence of neck pain in women was higher than that in men (69.1% vs 48.6%, P<0.01) . The prevalence of neck pain was related to length of service, self-assessment of fatigue, working hours per week, working in the same workshop, rest days per shift, and accumulated rest time per shift (P<0.05) . Multivariate logistic regression analysis showed that the risk of neck pain in women was 2.434 times higher than that in men; The risk of neck pain increased by 18.9% for each hour of work per week; Rest during work was a protective factor for neck pain. The number of rest per shift increased and the risk of neck pain decreased (r=0.405, 0.311, 0.302, 95%CI=0.205~0.803, 0.169~0.572, 0.142~0.642, P<0.05) . Conclusion: The annual prevalence of neck pain was higher in automobile assemblers. Enterprises should fully consider the influencing factors such as gender, working hours per week and the number of breaks when arranging production.

[Prognosis analysis of local recurrence after excision of breast phyllodes tumors].

Objective: To examine treatment outcomes of breast phyllodes tumors and the prognosis factors of local recurrence. Methods: This retrospective cohort study included 276 patients who underwent surgical resection at Breast Center, Peking University People's Hospital from January 2011 to December 2019. Tumor subtype and histopathological features were determined from pathology reports, and the deadline of follow-up was September 30th, 2020. All 276 patients underwent open surgery, including 17 patients of mastectomy, and 259 patients of lumpectomy. The enrolled patients were all female, with age of (41.5±11.3) years (rang: 11 to 76 years), and tumor diameter of 35(28) mm (M(QR)). The Kaplan-Meier method and Log-rank test were used for survival analysis. The multivariate analysis was implemented using the Cox proportional hazard model. Results: According the pathologic test, there were 191 patients of benign phyllodes tumor, 67 patients of borderline tumor and 18 patients of malignant tumor. There were 249 patients with a follow-up of more than 6 months, and 14.1% (35/249) had local recurrence. The time-to-recurrence was (28.6±22.2) months (range: 2 to 96 months), (29.1±18.1) months (range: 2 to 80 months), (32.1±30.1) months (range: 5 to 96 months) and (12.0±6.9) months (range: 8 to 20 months) for benign, borderline and malignant phyllodes tumors. Tumor diameter (≥100 mm vs.<50 mm, HR=3.968, 95%CI: 1.550 to 10.158, P=0.004) and malignant heterologous element (yes vs. no, HR=26.933, 95%CI: 3.105 to 233.600, P=0.003) were prognosis factors of local recurrence. One death from malignant phyllodes occurred after distant metastasis. The 3-year disease-free survival rates of benign, borderline and malignant phyllodes tumor were 88.2%, 81.7% and 81.4% (P=0.300). Conclusion: Phyllodes tumors have a considerable local recurrence rate, which may be associated with tumor diameter and malignant heterologous element.

[Cumulative noise exposure and the risk of high-frequency hearing loss relationships].

Objective: To explore the dose-response relationship between cumulative noise exposure and high-frequency hearing loss, and further to provide a basis for the control of occupational hazards of noise. Methods: A Meta-analysis of dose-response relationships was performed on the data of eligible literatures published in China from January 2000.1 to December 2019.12. Results: The initial combined Odds Ratio (OR) and its 95%CI in the Meta-analysis were 1.10 (1.08-1.12) . As the Begg's funnel plot and Egger's test indicated publication bias (t=5.97, P<0.01) , the Trim-and-Fill Method was used for OR value adjustment. The adjusted-OR was 1.09 (1.07-1.12) ; sensitivity analysis showed that the results of this Meta-analysis have high stability; subgroup analysis indicated that the ORs of the steady-state noise group and the non-steady-state noise group were 1.10 (1.08-1.12) and 1.14 (1.07-1.21) , the ORs of the old standard group and the new standard group were 1.10 (1.08-1.12) and 1.11 (1.00-1.24) , respectively. The nonlinear dose-response relationship curve demonstrated that the risk of high-frequency hearing loss increases rapidly after CNE reaches 95 dB (A) ·years. Conclusion: There is a definite dose-response relationship between CNE and high-frequency hearing loss, which can be used to predict the risk of high-frequency hearing loss in noisy workers.

[Investigation on high-frequency hearing loss of noise workers in an automobile factory].

Objective: To investigate the high-frequency hearing loss (HFHL) of workers in an automobile factory and its influencing factors, so as to provide a scientific basis for occupational health management of noise workers. Methods: From March to July 2019, 2647 workers from an automobile factory were selected as the research objects by cluster sampling method. The basic personal information (such as gender, age, education level, height, weight, etc.) , history of ear disease, the history of detonation, history of exposure to ototoxic drugs, history of exposure to occupational noise, etc., were investigated by questionnaire and occupational health examination. Chi-square test was used to compare the detection rates of HFHL in different populations, and multivariate logistic regression model was used to analyze the influencing factors of HFHL. Results: The noise level of 2647 individual workers ranged from 75.0 dB (A) to 92.0 dB (A) , with an average of (84.14±2.47) dB (A) . The detection rate of HFHL was 17.2% (456/2647) . There were significant differences in the the detection rate of HFHL among workers of different gender, age, educational level, working age, noise exposure level, diabetes history, detonation history, smoking and drinking workers (P<0.05) . Multivariate logistic regression analysis showed that male, age ≥30 years old, smoking and noise exposure were risk factors for HFHL (P<0.05) . Conclusion: The detection rate of HFHL in automobile factory workers is high. Gender, age, smoking and noise are the influencing factors of HFHL. It is necessary to strengthen the noise control in the workplace and guide workers to choose healthy lifestyle.

[Epidemiological analysis and screening mode of breast cancer screening in Fujian province from 2015 to 2018].

Objective: To analyze the screening results of breast cancer in rural women in Fujian Province from 2015 to 2018, and to explore the screening mode of breast cancer. Methods: Breast cancer screening was provided for 35-64 years old rural women in Fujian province. Color Doppler ultrasound was used as the primary screening method. Suspected patients were referred to mammography. Color Doppler ultrasound and breast X -ray 4-5 grade were diagnosed by pathology. Results: The incidence of breast cancer from 2015 to 2018 was 56.96/10 million, 94.41/10 million, 71.61/10 million, and 73.05/10 million, respectively. And the peak age of breast cancer was (46-55) years. From 2015 to 2018, the proportion of cancer in situ showed an overall upward trend. The sensitivity of color Doppler ultrasound was 79.06%, and the sensitivity of mammography for those diagnosed abnormally by ultrasound was 91.88%. Conclusion: Breast cancer screening for women of the right age is an important measure to raise the rate of early diagnosis and early treatment and reduce the mortality of breast cancer. Screening mode based on breast ultrasound is the most suitable technology. We need to further expand the coverage of screening, improve the screening system and process, and ensure the health of women.

[Study on the effects of noise on hypertension and hyperglycemia among occupational workers].

Objective: To study the effect of noise on hypertension and hyperglycemia among occupational workers. Methods: Total 670 workers in an automobile manufacturing company were selected as the subjects of physical examination in 2017. According to the noise exposure or not, the subjects were divided into control group (no noise exposure) 143 and contact group (noise exposure) 527. Questionnaire survey and physical examination were conducted. The measurement data were analyzed by t-test, and the count data and grade data were analyzed by χ(2) test. The influence of noise on blood glucose, heart rate, blood pressure and other indicators was analyzed by logistic regression, and the OR and 95%CI of each risk factor were calculated. Results: The average age of the control group and the contact group was no significant difference (P>0.05) . There were 139 (20.7%) cases of high systolic pressure, 154 (23.0%) cases of high diastolic pressure, 63 (9.4%) cases of hyperglycemia, 29 (4.3%) cases of tachycardia. Compared with the control group, there were significant differences in systolic blood pressure, diastolic blood pressure and blood glucose in the contact group (P<0.05) . Compared with the control group, the systolic blood pressure, diastolic blood pressure and blood glucose of the subjects in the corresponding age contact group increased significantly (P<0.05) . The years of noise exposure were protective factors for systolic and diastolic blood pressure (OR=0.970, 0.973) . Conclusion: Noise exposure may increase blood pressure and blood sugar of occupational workers, but the effect on heart rate can not be determined.

[Computer Aided Diagnosis system of breast ultrasound based on support vector machine: a clinical analysis].

Objective: To investigate the value of based on support vector machine (SVM) breast ultrasonography technology of Computer-Assisted diagnosis (CAD) for differential diagnosis of benign and malignant breast masses. Methods: Total of 143 patients who had 151 breast masses were collected in Fujian Maternity and Children Health Hospital or The Fist Affiliated Hospital of Fujian Medical University from June 2014 to December 2015. Based on pathological results as the gold standard, the diagnostic efficiency of CAD and ultrasonography were compared. Results: The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ultrasonography were 80.1%, 71.0%, 76.8%, 80.0% and 72.1%, respectively. And the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of CAD were 96.6%, 90.3%, 94.0%, 93.5% and 94.9%, respectively. The specificity, accuracy, positive predictive value and negative predictive of CAD technology were significantly higher than those of ultrasonography (P<0.05). The area under the receiver operator characteristic curve of ultrasonography and CAD were 0.759 and 0.935 respectively, with significant difference (P<0.05). Conclusions: CAD has a higher specificity and accuracy rate than ultrasonography in the diagnosis of breast masses. It could help to differentiate benign from malignant breast masses.

Epidemiological characteristics and influential factors of hand, foot and mouth disease (HFMD) reinfection in children in Anhui province.

Hand, foot and mouth disease (HFMD) is an acute contagious condition caused by a spectrum of human enteroviruses. HFMD reinfection is common in the absence of cross-protection from other virus subtypes. This study focused on reinfection in children in Anhui province, China between 2008 and 2013 using surveillance system data. We classified 8960 cases as reinfected, corresponding to a rate of 2·02%. The reinfection rate was higher in boys than in girls [odds ratio (OR) 1·27, 95% confidence interval (CI) 1·21-1·32, P < 0·001], children aged < 3 years (OR 3·82, 95% CI 3·58-4·07, P < 0·001), and children living in rural areas (OR 1·09, 95% CI 1·04-1·14, P = 0·001). The reinfection rate in children who were originally infected with non-enterovirus A71 (non-EVA71) enteroviruses was higher than those infected with EVA71 (OR 1·36, 95% CI 1·02-1·80, P = 0·034). Influential factors of reinfection rate included annual incidence (ß coefficient = 0·715, P = 0·002) and the proportion of EVA71 in patients with mild HFMD (ß coefficient = -0·509, P = 0·018). These results demonstrate that boys aged <3 years, especially those in rural areas or regions with a lower EVA71 proportion are more prone to reinfection, and specific health education programmes should be developed to protect these susceptible populations.

Role of methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in polycystic ovary syndrome risk.

Polycystic ovary syndrome is one of the most frequently encountered endocrine malfunctions. Methylenetetrahydrofolate reductase (MTHFR) plays a vital role in folate metabolism, DNA methylation, and RNA synthesis. We carried out a study to investigate the association between MTHFR C677T and A1298C genetic variations and the risk of polycystic ovary syndrome in a Chinese population. We recruited 244 patients and 257 control subjects from an Inner Mongolian Medical University to this hospital-based, case-control study. The genotyping of the MTHFR C677T and A1298C polymorphisms was carried out using polymerase chain reaction coupled with restriction fragment length polymorphism. Using multiple logistic regression analysis, we found that the TT genotype and the T allele of MTHFR C677T carriers showed increased risk of polycystic ovary syndrome compared with the wild-type genotype or allele carriers. The adjusted ORs for the TT genotype and the T allele of MTHFR C677T were 1.84 (1.05-3.26) and 1.38 (1.06-1.81), respectively. Subjects carrying the CC genotype (OR = 3.98, 95%CI = 1.60-11.23) and the C allele (OR = 1.46, 95%CI = 1.07-2.00) of MTHFR A1298C had an elevated risk of polycystic ovary syndrome compared with the AA genotype and A allele carriers. In conclusion, our study suggests that the MTHFR C677T and A1298C polymorphisms may have contributed to the risk of polycystic ovary syndrome in the Chinese women investigated. Further research involving a greater number of individuals is warranted to confirm our results.

In vitro and in vivo studies on the inhibitory effects of myocardial cell culture medium on growth of a human lung adenocarcinoma cell line, A549.

BACKGROUND: Although the heart is one of the body's vital organs, with an abundant blood supply, metastasis to the heart is considered rare. In a previous study, we found that the myocardial microenvironment might contain a low molecular weight natural tumour suppressor. The present study was designed to investigate the inhibitory effect of cardiac myocyte-conditioned medium (cmcm) on the growth of A549 human lung adenocarcinoma cells in vitro and in vivo. METHODS: An mtt assay was used to detect the inhibition ratio with respect to A549 proliferation. Human lung adenocarcinoma cells (A549 cell strain) were transplanted subcutaneously into nude mice to produce tumours. The xenograft tumour growth in mice was observed after selected drug administration. RESULTS: After treatment with cmcm and cisplatin (Cis), A549 cell viability significantly declined (p < 0.001). The cell viability in the cmcm and Cis groups were 53.42% ± 3.45% and 58.45% ± 6.39% respectively. Growth of implanted tumour cells in vivo was significantly inhibited in the cmcm group, the group treated with recombinant human adenovirus-p53, and the Cis-treated group compared with a control group. The inhibition rates were 41.44% in the cmcm group, 41.34% in the p53 group, and 64.50% in the Cis group. Lung metastasis capacity was significantly reduced in the presence of cmcm (p < 0.05). Lung metastasis inhibition rates in mice were 56.52% in the cmcm group, 47.83% in the p53 group, and 82.61% in the Cis group. With cmcm, the lives of A549-tumour-bearing mice could be significantly prolonged without any effect on weight loss. CONCLUSIONS: Use of cmcm has the effect of reducing A549 cell viability, tumour volume, and lung metastasis rate, while prolonging survival duration without severe toxicity.

Phylogeography of pink pineapple mealybugs, Dysmicoccus brevipes (Cockerell) reveals the history of pineapple introduction and cultivation in China.

The pink pineapple mealybug (PPM), Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), is a widespread plant-sucking insect of considerable concern because it transmits the pineapple mealybug wilt-associated virus. Its distribution is closely linked with its host, the pineapple [Ananas comosus (L.) Merrill] because of its wingless and parthenogenetic characteristics. To investigate the history of D. brevipes introduction and the cultivation of pineapple in China, samples of D. brevipes were collected from the main pineapple production region in China, and from Thailand, and the mitochondrial cytochrome c oxidase subunit I (COI) gene was analyzed. Homologous sequences of D. brevipes COI from Brazil, Thailand, and Philippines that are deposited in GenBank were compared. Phylogenetic analyses suggest there are close genetic relationships between PPM populations from Hawaii, Brazil, the Philippines, and from Thailand and China, which probably originate from South America. It is suggested that most PPMs in China were introduced from South America by way of Southeast Asia, being accompanied by the pineapple seedling. Conversely, some PPMs represented by Haplotype-WN from Wanning of China, and Lampang of Thailand were found to differ greatly from populations in Hawaii, Brazil, the Philippines, Thailand, and China. It is possible that another route was used for the introduction and distribution of pineapple, or that pineapple might have originated in Southeast Asia.

Source identification through social networks in an epidemiological investigation of a hepatitis A outbreak at an elementary school in Anhui province, China.

In May 2011, the Center for Disease Control and Prevention of a Chinese county found a rapid increase in the number of hepatitis A case notification; these were traced to an outbreak in an elementary school. Twenty-eight cases aged between 7 and 13 years with onset between 7 May and 8 June were serologically confirmed. Network method was conducted to reconstruct an outbreak network and to quantify the relative importance of those involved in the outbreak. A case-control study was used to study the association between the outbreak and putative risk factors. The network analysis suggested this was a disseminated outbreak originating from a 4-year-old boy with propagated spread. Evidence from the case-control study supported consumption of well water as a potential risk factor; however, this was unable to be established through field investigation. Outbreak networks can be used to identify the possible source of infectious disease outbreak, especially when the environmental investigation information is negative or not available.

Polymorphism of the OLR1 3'UTR potential microRNA binding site and risk of Alzheimer's disease: a meta-analysis.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that contributes to dementia in the elderly population. Genome-wide linkage analysis has identified chromosome 12p as the AD-susceptible region, which includes lectin-like oxidized low-density lipoprotein receptor 1 (OLR1). The OLR1 +1073 C/T single-nucleotide polymorphism is located in the 3'-untranslated region of the gene and may influence the binding of regulatory microRNAs (miRNAs) and OLR1 protein homeostasis. A number of studies have reported an association between this variant and AD. However, the results are controversial. A meta-analysis of case-control studies examining the relationship between the OLR1 +1073 C/T single-nucleotide polymorphism and AD risk was performed. Five studies were selected that included 2419 cases and 2381 controls. The results revealed a significantly decreased AD risk in the recessive model (TT vs TC + CC: odds ratio (OR) = 0.79, 95% confidence interval (CI) = 0.65-0.96). The control group in one of the studies was in Hardy-Weinberg disequilibrium, so we performed additional meta-analysis excluding this study. The significance was much more pronounced in the recessive model (TT vs TC + CC: OR = 0.72, 95%CI = 0.62-0.85). Using miRanda and RNA hybrid methods, the polymorphic allele was shown to influence the binding of various miRNAs. Our results suggested that the +1073 C/T polymorphism decreased the risk of AD. The polymorphic allele was also predicted to affect the binding site of many miRNAs, which may explain the relationship between the +1073 C/T variant and AD.

Effects of lovastatin on hepatic expression of the low-density lipoprotein receptor in nephrotic rats.

To investigate the effect of the HMG-CoA reductase inhibitor lovastatin on the expression of the receptor for hepatic low-density lipoprotein (LDL) in a rat model with kidney disease, and to identify the mechanisms in statin treatment of nephrotic syndrome with hyperlipidemia, a rat model with nephrotic syndrome was established. Thirty male Sprague-Dawley rats were treated with lovastatin for 2 weeks using gavage. The expression of protein and mRNA of the LDL receptor in the rat liver was detected with Western blot and RT-PCR, respectively, and blood-biochemical indices were also recorded for each group. Compared with the untreated control group, lovastatin treatment significantly decreased the levels of serum total cholesterol, LDL cholesterol, triglycerides, and urinary protein. In addition, lovastatin treatment significantly increased the levels of serum albumin and hepatic LDL receptor proteins, but had no effect on the expression of hepatic LDL receptor mRNA. Treatment with lovastatin markedly increased the expression of the hepatic LDL receptor in rats with nephrotic syndrome, which was accompanied by significantly improved hyperlipidemia.

First Report of Leaf Spot Caused by Nigrospora oryzae on Dendrobium candidum in China.

Dendrobium (Dendrobium candidum Wall. ex Lindl.) is a perennial herb in the Orchidaceae family. It has been used as traditional medicinal plant in China, Malaysia, Laos, and Thailand (2). Fungal disease is one of the most important factors affecting the development of Dendrobium production. During summer 2012, chocolate brown spots were observed on leaves of 2-year-old Dendrobium seedlings in a greenhouse in Hangzhou, Zhejiang Province, China, situated at 30.26°N and 120.19°E. Approximately 80% of the plants in each greenhouse were symptomatic. Diseased leaves exhibited irregular, chocolate brown, and necrotic lesions with a chlorotic halo, reaching 0.8 to 3.2 cm in diameter. Affected leaves began to senesce and withered in autumn, and all leaves of diseased plants fell off in the following spring. Symptomatic leaf tissues were cut into small pieces (4 to 5 mm long), surface-sterilized (immersed in 75% ethanol for 30 s, and then 1% sodium hypochlorite for 60 s), rinsed three times in sterilized distilled water, and then cultured on potato dextrose agar (PDA) amended with 30 mg/liter of kanamycin sulfate (dissolved in ddH2O). Petri plates were incubated in darkness at 25 ± 0.5°C, and a grey mycelium with a white border developed after 4 days. Fast-growing white mycelia were isolated from symptomatic leaf samples, and the mycelia became gray-brown with the onset of sporulation after 5 days. Conidia were unicellular, black, elliptical, and 11.4 to 14.3 µm (average 13.1 µm) in diameter. Based on these morphological and pathogenic characteristics, the isolates were tentatively identified as Nigrospora oryzae (1). Genomic DNA was extracted from a representative isolate F12-F, and a ~600-bp fragment was amplified and sequenced using the primers ITS1 and ITS4 (4). BLAST analysis showed that F12-F ITS sequence (Accession No. KF516962) had 99% similarity with the ITS sequence of an N. oryzae isolate (JQ863242.1). Healthy Dendrobium seedlings (4 months old) were used in pathogenicity tests under greenhouse conditions. Leaves were inoculated with mycelial plugs (5 mm in diameter) from a 5-day-old culture of strain F12-F, and sterile PDA plugs served as controls. Seedlings were covered with plastic bags for 5 days and maintained at 25 ± 0.5°C and 80 ± 5% relative humidity. Eight seedlings were used in each experiment, which was repeated three times. After 5 days, typical chocolate brown spots and black lesions were observed on inoculated leaves, whereas no symptoms developed on controls, which fulfilled Koch's postulates. This shows that N. oryzae can cause leaf spot of D. candidum. N. oryzae is a known pathogen for several hosts but has not been previously reported on any species of Dendrobium in China (3). To our knowledge, on the basis of literature, this is the first report of leaf spot of D. candidum caused by N. oryzae in China. References: (1) H. J. Hudson. Trans. Br. Mycol. Soc. 46:355, 1963. (2) Q. Jin et al. PLoS One. 8(4):e62352, 2013. (3) P. Sharma et al. J. Phytopathol. 161:439, 2013. (4) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.