Detection of microorganisms in hospital air before and during the SARS-CoV-2 pandemic.

OBJECTIVE: Microorganisms present a global public health problem and are the leading cause of hospital-acquired infections. Therefore, it is essential to study the prevalence of microorganisms in hospital environments. The conclusion from such a study can contribute to identify the areas most likely to be contaminated in a hospital and appropriate measures that can decrease the exposure risk. MATERIALS AND METHODS: The prevalence of microorganisms in hospital air was examined in different departments by obtaining air samples with an impactor before and during the SARS-CoV-2 pandemic. A total of 2145 microorganisms were identified, and the corresponding data were jointly analyzed by area, sampling period, and concentration. RESULTS: The most frequently detected microorganisms in hospital air were Staphylococcus, Micrococcus, Neisseria, and fungi, and the more polluted departments were the hemodialysis department, respiratory department, treatment room, and toilet. Significant differences were found between the concentration of bacteria and fungi before and during the pandemic, which could be related to multiple environmental conditions. Furthermore, SARS-CoV-2 was negative in all the air samples. CONCLUSIONS: Overall, this study confirmed the existence and dynamic characteristics of airborne microorganisms in a hospital. The results contribute to the adaptation of specific measures which can decrease the exposure risk of patients, visitors, and staff.

[Characteristics and predictors of postoperative outcome of Crohn disease patients requiring abdominal surgery: a series of 1 048 cases from a single inflammatory bowel disease centre].

Objective: To examine the clinical characteristics, the potential relative factors for postoperative abdominal septic complications, and prognosis factors of surgical recurrence of Crohn disease (CD) patients after the first surgery. Methods: All the CD patients from Department of General Surgery, Jinling Hospital, Medical School of Nanjing University who had undergone at least one abdominal surgery from January 2007 to December 2017 were included for retrospective analysis. Hospital records were reviewed for information on clinical characteristics. Relative factors of postoperative abdominal septic complications were accessed by Logistic regression models, and prognosis factors of surgical recurrence were accessed by Cox proportional hazards regression models. Results: There were 1 048 patients included (733 males and 315 females), accounting for 1 513 operations. The age was 31(17) years and the length of resected small bowel was 30.0(40.0) cm at the first resection, 20.0(35.0) cm at the second resection, and 20.0(23.5) cm at the third resection. The length of resected small bowel was 25.0(40.0) cm at any resection. At the first abdominal surgery, 70.99%(744/1 048) patients were aged between 17 and 40 years, 66.98%(702/1 048) patients had ileocolonic disease, and 60.40%(633/1 048) patients had penetrating behavior. Penetrating behavior (OR=8.594, 95%CI: 3.397 to 21.740, P<0.01) and current smoking status (OR=2.671, 95%CI: 1.044 to 6.832, P=0.040) were significantly associated with an increased risk of postoperative septic complications, whereas staged operation (OR=0.360, 95%CI: 0.184 to 0.707, P=0.003) was associated with a decreased risk. Male gender (HR=1.500, 95%CI: 1.128 to 1.995, P=0.005), upper gastrointestinal disease (HR=1.526, 95%CI: 1.033 to 2.255, P=0.034), penetrating behavior (HR=1.506, 95%CI: 1.132 to 2.003, P=0.005) and emergency surgery (HR=1.812, 95%CI: 1.375 to 2.387, P<0.01) were significantly associated with an increased risk of postoperative surgical recurrence, whereas staged operation (HR=0.361, 95%CI: 0.227 to 0.574, P<0.01) was significantly associated with a decreased risk. Conclusions: In this cohort of CD patients receiving abdominal surgery from an inflammatory bowel disease center, the median age was 31 years and the median length of resected small bowel was 30 cm, at first resection. Patients who have risk factors of adverse postoperative outcome may be benefited from staged surgical approach.

[A comparative study on diagnosis of silicosis by digital and high kV film-screen chest radiography].

Objective: To explore the feasibility of soft copy image of chest digital radiography (DR(SC)) in pneumoconiosis diagnosis by observing the reading effect of DR(SC) and comparing it with high kV film-screen chest radiography (FSR(HkV)) . To provide a basis for the establishment of a regional information network platform for pneumoconiosis diagnosis. Methods: A total of 119 miners who were exposed to silica dust and engaged in copper or lead-zinc mining were collected by the Third People's Hospital of Yunnan from October 2017 to August 2019. The pulmonary X-ray findings of DRSC and FSR(HkV) in each case were independently judged and diagnosed by three experienced diagnostic physicians, and the final decision was made according to the consensus of most doctors. The consistency of the two imaging methods was analyzed by observing the main small opacity shape, the overall density, the range of distribution, the aggregation of the small opacity and the big opacity, and the diagnosis stage. Results: there were 118 males and 1 female with an average age of 46.21 years. Average exposure time 7.38 years. The pulmonary X-ray findings of 113 cases with two imaging methods were mainly the round small opacity of p,q and r,but the reticular irregular opacity were not prominent, Only one case of FSR(HkV) judgment p shape and DR(SC) judgment q shape were observed, The coincidence rate was 99.12% (112/113) . huger opacity were observed in the other 6 cases. The coincidence rate was 95.51% (4/89) between pneumoconiosis-free and stageⅠ, and there was no significant difference between stageⅡand stage Ⅲ (30/30, P>0.05) . Conclusion: The x-ray findings of Silicosis with small round shadow in lung can be used by DR(SC) in diagnosis and staging.

[Anti-mouse CD(52) antibody ameliorates colitis through suppressing Th1/17 mediated inflammation and promoting regulatory T cell response in interleukin-10 deficient mice].

In this study, we evaluated the therapeutic effects and possible mechanisms of anti-CD(5)2 treatment on interleukin-10 (IL-10) deficient mice. Anti-mouse CD(52) monoclonal antibody was administrated to C3H. IL-10(-/-)mice. The disease activity index, histological grading of colitis, serum Th1/17 related cytokines, percentage of CD(25+)Foxp3(+) T cells in colon as well as CD(25), Foxp3 gene expression were measured. Our data suggested that anti-CD(52) treatment inhibited colitis in C3H.IL-10(-/-)mice and it might be related to the suppression of Th1/17 related inflammation and the promotion of regulatory T cell differentiation.

[Analysis of blood lead level of children living around lead-zinc mines].

Objective: To investigate the blood lead level of children living around lead-zinc mining areas, in order to analyze its distribution features of the population. Methods: In August 2016, three natural villiages around lead-zinc mines were selected randomly as survey sites, which were grouped A, B and C according to each distances from the center field, totally 1 379 children from the three villages were selected by cluster random sampling method as the investigation subjects, and their elbow peripheral vein blood samples were collected to determine the blood lead level by graphite furnace atomic absorption spectrometry. The distribution features of blood lead in different district, gender and age groups were compared and analyzed. Results: The median and quartile range of blood lead were 0.066 and 0.058 mg/L respectively. The blood lead levels of 341 children were esceeding 100 µg/L and that account for 24.73%. The median blood lead showed statistical significant differrnce among three groups (P<0.01) , and the medians from high to low were: 0.075 mg/L (A) , 0.065 mg/L (B) and 0.059 mg/L (C) respectively. The average blood lead of male was higher than that of female (P<0.01) . There was significant difference in blood lead levels among different aged groups (P<0.01) , and the high blood lead rate dicreased with the increase of age (P<0.01) . Results of multivariate logistic regression analysis showed that there was a high risk of excessive lead in the blood lead of boys aged 1-6 years from the center of the area. Conclusion: The blood lead level of children living around lead-zinc mining areas is relatively high. There are difference in district distribution, gender and age.

[The value of postoperative C-reactive protein in predictive diagnosis of postoperative intra-abdominal septic complications for patients with Crohn disease].

OBJECTIVE: To analyze the value of postoperative C-reactive protein (CRP) in predictive diagnosis of postoperative intra-abdominal septic complications (IASC) for patients with Crohn disease (CD). METHODS: Clinical data of patients with CD received intestinal resection and anastomosis surgery at Research Institute of General Surgery, Jinling Hospital from January 2011 to January 2015 were analyzed. Patients were divided into two groups by whether suffer from IASC 1 month after surgery, including IASC group and no-IASC group. Propensity score matching method was used to match the general clinical data. A total of 54 patients were analyzed, including IASC 17 cases, no-IASC 37 cases. Postoperative CRP at 1-day and 3-day were compared between the two groups using t test. Receiver operator characteristic (ROC) cure was used to analyze the value of postoperative CRP in predictive diagnosis of IASC. RESULTS: IASC group had higher levels of CRP at 1-day ((78±13) mg/L vs. (54±19) mg/L, t=4.633, P=0.000) and 3-day ((103±19) mg/L vs. (69±21) mg/L, t=5.859, P=0.000) after surgery than no-IASC group. ROC analysis showed that the CRP 3-day after surgery cut-off point value of 81.45 mg/L, as used for the predictive diagnosis of IASC, provided a sensitivity of 94.1%, a specificity of 82.9%, an area under the curve of 0.90, better than CRP 1-day after surgery. CONCLUSION: Postoperative CRP can be used as a predictive diagnosis of IASC for CD patients received intestinal resection and anastomosis surgery.

Correction: Optofluidic lens with low spherical and low field curvature aberrations.

Correction for 'Optofluidic lens with low spherical and low field curvature aberrations' by H. T. Zhao et al., Lab Chip, 2016, 16, 1617-1624.

Optofluidic lens with low spherical and low field curvature aberrations.

This paper reports an optofluidic lens with low spherical and low field curvature aberrations through the desired refractive index profile by precisely controlling the mixing between ethylene glycol and deionized water in an optofluidic chip. The experimental results demonstrate that the spherical aberration is reduced to 19.5 µm and the full width at half maximum of the focal point is 7.8 µm with a wide divergence angle of 35 degrees. In addition, the optofluidic lens can focus light at different off-axis positions on the focal plane with Δx' < 6.8 µm and at opposite transverse positions with |Δy - Δy'| < 5.7 µm. This is the first demonstration of a special optofluidic lens that significantly reduces both the spherical and field curvature aberrations, which enhances the focusing power and facilitates multiple light source illumination using a single lens. It is anticipated to have high potential for applications such as on-chip light manipulation, sample illumination and multiplexed detection.

Neutron diffraction study of the (BiFeO3)1-x(PbTiO3)x solid solution: nanostructured multiferroic system.

Neutron diffraction studies performed on the solid solution of (BiFeO(3))(1-x)(PbTiO(3))(x) reveal a mixture of two nanoscale phases with different crystal structures: a rhombohedral BiFeO(3)-based phase and a tetragonal PbTiO3-based phase. The ratio of Fe(3)+ and Ti(4)+ ions in the two phases is practically constant; only the proportion of the phases changes. The magnetic moments in the BiFeO(3)-based phase, in contrast to BiFeO(3), deviate from the basal plane. The temperature evolutions of the spin components along the hexagonal axis and within the perpendicular plane are different, leading to a spin re-orientation transition. The antiferromagnetic order in the PbTiO(3)-based phase corresponds to a simple structure with the propagation vector (1/2, 1/2, 1/2). The temperature dependence of the antiferromagnetic moment in the tetragonal phase at x = 0.5 indicates a canted antiferromagnetic order and a net ferromagnetic moment. A strong magnetic coupling between the two constituting phases due to the nanoscale character of the phases and well-developed interface between nanoparticles has been observed. The system of (BiFeO(3))(1-x)(PbTiO(3))(x) demonstrates an interesting scenario, where the proximity effects in the unstable system play a crucial role in the appearance of the unusual magnetic properties.

A pseudo-planar metasurface for a polarization rotator.

New demonstrations of effective interaction between light and artificially electromagnetic interface, or the metasurface, have stimulated intensive research interests on control of light to realize applications in beam steering, optical imaging and light focusing, etc. Here we reported a new type of planar metasurface of which every individual metamolecule is single metallic layer with stereo structure and the metasurface is name as Pseudo-Planar Metasurface (PPM). The metamolecule of the PPM is a chiral structure and therefore derives significant optical activity.

Adenovirus-mediated bone morphogenetic protein-2 gene transfection of bone marrow mesenchymal stem cells combined with nano-hydroxyapatite to construct bone graft material in vitro.

To study the adhesion, proliferation and expression of bone marrow mesenchymal stem cells (BMSCs) on nano-hydroxyapatite (Nano-HA) bone graft material after transfection of adenovirus-mediated human bone morphogenetic protein-2 expression vector (Ad-BMP-2). BMSCs were transfected using Ad-BMP-2. Immunohistochemistry and Western blot were used to detect BMP-2 expression in transfected cells. After transfection, BMP-2 protein was highly expressed in BMSCs; MTT test assay showed that the Nano-HA bone graft material could not inhibit in vitro proliferation of BMSCs. Ad-BMP-2-transfected BMSCs are well biocompatible with Nano-HA bone graft material, the transfected cells in material can secrete BMP-2 stably for a long time.

Microelectromechanical Maltese-cross metamaterial with tunable terahertz anisotropy.

Dichroic polarizers and waveplates exploiting anisotropic materials have vast applications in displays and numerous optical components, such as filters, beamsplitters and isolators. Artificial anisotropic media were recently suggested for the realization of negative refraction, cloaking, hyperlenses, and controlling luminescence. However, extending these applications into the terahertz domain is hampered by a lack of natural anisotropic media, while artificial metamaterials offer a strong engineered anisotropic response. Here we demonstrate a terahertz metamaterial with anisotropy tunable from positive to negative values. It is based on the Maltese-cross pattern, where anisotropy is induced by breaking the four-fold symmetry of the cross by displacing one of its beams. The symmetry breaking permits the excitation of a Fano mode active for one of the polarization eigenstates controlled by actuators using microelectromechanical systems. The metamaterial offers new opportunities for the development of terahertz variable waveplates, tunable filters and polarimetry.

Precise control of the number of walls formed during carbon nanotube growth using chemical vapor deposition.

We demonstrate a one-step approach for selecting the number of walls formed during carbon nanotube (CNT) growth by catalytic decomposition of CH(4) over Fe-Mo/MgO catalysts. Scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), thermal gravimetric analysis (TGA) and Raman spectroscopy analyses indicate that high purity single-walled, double-walled and triple-walled carbon nanotubes can be synthesized by tuning the Fe:Mo atomic ratio of catalysts. The results reveal that the concentration of Mo in the catalyst plays an important role in the size of catalyst particles and in the deposition rate of carbon atoms during CNT growth. Thus, the wall numbers of CNTs can be controlled precisely.

A rare Y chromosome constitutional rearrangement: a partial AZFb deletion and duplication within chromosome Yp in an infertile man with severe oligoasthenoteratozoospermia.

We report a case of an infertile man with severe oligoasthenoteratozoospermia with a partial azoospermia factor b (AZFb) deletion and duplication region within chromosome Yp11.2. The hormonal profile was normal for serum concentrations of follicle-stimulating hormone, luteinizing hormone, testosterone and oestradiol. The patient, who showed a 46,XY karyotype, had an approximate 2.4 Mb inherited duplication region in Yp11.2 and a de novo partial AZFb deletion, which spanned 5.25 Mb including eight protein coding genes and four non-coding transcripts, but did not remove the RBMY gene family. Both proximal and distal breakpoints of the deletion were outside any palindromic region or inverted repeat sequence and intra-chromosomal non-allelic homologous recombination could not have been the deletion mechanism. The partial AZFb deletion in our case diminished sperm production, but did not completely extinguish spermatogenesis. Considering severe oligozoospermia, spermatozoa in the patient's ejaculate were used for intracytoplasmic sperm injection, resulting in two twin pregnancies.

Optofluidic refractometer using resonant optical tunneling effect.

This paper presents the design and analysis of a liquid refractive index sensor that utilizes a unique physical mechanism of resonant optical tunneling effect (ROTE). The sensor consists of two hemicylindrical prisms, two air gaps, and a microfluidic channel. All parts can be microfabricated using an optical resin NOA81. Theoretical study shows that this ROTE sensor has extremely sharp transmission peak and achieves a sensitivity of 760 nm∕refractive index unit (RIU) and a detectivity of 85 000 RIU(-1). Although the sensitivity is smaller than that of a typical surface plasmon resonance (SPR) sensor (3200 nm∕RIU) and is comparable to a 95% reflectivity Fabry-Pérot (FP) etalon (440 nm∕RIU), the detectivity is 17 000 times larger than that of the SPR sensor and 85 times larger than that of the FP etalon. Such ROTE sensor could potentially achieve an ultrahigh sensitivity of 10(-9) RIU, two orders higher than the best results of current methods.

First Report of Cucurbit yellow stunting disorder virus on Melon in China.

Melon (Cucumis melo L.) plants in commercial fields in Shanghai, Jiangsu, and Zhejiang exhibited stunting, deformation, interveinal chlorosis, and leaf mottling in the spring of 2008. In addition, adult and immature whiteflies (Bemisia tabaci biotype B) were present in these melon fields. Thirty-two symptomatic leaf samples were collected from these fields for further analysis (9 from Nanhui County in Shanghai, 11 from Fengxian County in Shanghai, 6 from Kunshan County of Jiangsu, and 6 from Jiashan County of Zhejiang). Total RNA was extracted from these samples along with asymptomatic control plants and screened for the presence of Cucurbit yellow stunting disorder virus (CYSDV) by using primers specific to genes encoding coat protein (2) and HSP70h (1) of CYSDV through reverse transcription (RT)-PCR methods. RNA was successfully extracted from 31 of 32 symptomatic samples. All 31 symptomatic leaf samples tested with coat protein primers were positive for CYSDV and yielded the expected fragment length of 394 bp. The RT-PCR products of the coat protein gene from all 31 isolates were cloned and found to be identical in sequence. Thus, only one was deposited in GenBank (No. GU189240). The submitted sequence of the amplified part of the coat protein gene was 99% identical to the sequence of coat protein gene of CYSDV from Jordan, France, and Florida (GenBank Accession Nos. DQ903107, AY204220, and EU596528, respectively) and 98% identical to that of an isolate from Spain (GenBank Accession No. AJ243000). Similarly, all 31 samples were also positive for CYSDV with the primers specific to HSP70h and yielded the expected fragment length of 175 bp. The RT-PCR products of the HSP70h gene from these isolates were also cloned and found to be identical in sequence. The sequence of the amplified portion of the HSP70h gene was found to be identical to the sequence of HSP70h of CYSDV deposited in GenBank (No. AJ439690.2). CYSDV was noticed in all three surveyed regions and the percentage of disease incidence was approximately 68% in all these regions. The occurrence of CYSDV has been previously reported in Europe (Spain and France), southern Asia (Iran and Jordan), North America (United States and Mexico), and other countries (1). To our knowledge, this is first report of CYSDV in China. References: (1) Y.-W. Kuo et al. Plant Dis. 91:330, 2007. (2) J. E. Polston et al. Plant Dis. 92:1251, 2008.

First Report of Powdery Mildew Caused by Oidium neolycopersici on Tomato in China.

Tomato powdery mildew can cause remarkable reduction in fruit size and quality (4). In March of 2008, powdery mildew appeared as circular, white colonies on leaves, petioles, and stems of tomato plants grown in greenhouses in Shangqiu, Henan Province, China. The pathogenic fungus had unbranched conidiophores with an average length of 58.4 µm and width of 5.1 µm. Conidia were hyaline, elliptical, and were borne singly. Average length and width of conidia were 30.6 and 15.1 µm, respectively. Germ tubes were straight and formed at the ends or very close to the ends of conidia. Chasmothecium was not found in the collected samples. Different tomato cultivars and species, including Lycopersicon esculentum Mill (cvs. Moneymaker, Micro-Tom, Zaofen, Fenguo, and Zhongza series), L. peruvianum cv. LA2172, and L. hirsutum cv. G1.1560, were inoculated with a conidial suspension with a concentration of 5 × 104 conidia/ml. Plants developed powdery mildew symptoms as early as 4 days after inoculation. Susceptible symptoms developed on all L. esculentum cultivars, while L. peruvianum LA2172 and L. hirsutum G1.1560 displayed complete resistance, which is similar to the results of Bai et al 2004 (1) and Lindhout and Pet 1990 (3). Morphological characteristics of the pathogen on susceptible genotypes were similar to those from naturally infected plants. On the basis of the characteristics of the asexual stage, the pathogen was identified as an isolate of Oidium neolycopersici L. Kiss, which was confirmed by internal transcribed spacer (ITS) sequence analysis. PCR amplification and sequencing of the ITS region were performed with primers ITS1 and ITS4. The nucleotide sequence was assigned GenBank Accession No. EU486992, which had a 100% homology with 10 ITS sequences of O. neolycopersici in GenBank (Accession Nos. EU047559 to 047568) (2). In Asia, the spread of this pathogen has been recently reported in Japan (2). To our knowledge, this is the first report of tomato powdery mildew in China. Voucher specimens are available at the Specimen Center in the Department of Life Science, Shangqiu Normal University. References: (1) Y. Bai et al. Mol. Plant-Microbe. Interact. 18:354, 2005. (2) T. Jankovics et al. Phytopathology 98:529, 2008. (3) P. Lindhout and G. Pet. Tomato Gen. Coop. Rep. 40:19, 1990. (4) J. M. Whipps et al. Plant Pathol. 47:36, 1998.