[Threshold temperature and effective accumulative temperature of Periplaneta Americana].

Periplaneta americana is an important medicinal insect. A series of new drugs developed from it have remarkable clinical effects and are in great demand in the market. Because of unclear biology, the quality and yield of P. americana are affected. Understanding the developmental threshold temperature and effective accumulated temperature of P. americana can provide theoretical basis for standardized culture of P.americana. Under climate chamber, the threshold temperature and effective accumulated temperature for egg development of P. americana to were determined through effective accumulated temperature law. The threshold temperature was （15.8±0.71）°C, the effective accumulated temperature was 415.8±38.05 degree days. A model of the relationship between temperature and developmental rates was established.

Phylogenetic evidence for a fusion of archaeal and bacterial SemiSWEETs to form eukaryotic SWEETs and identification of SWEET hexose transporters in the amphibian chytrid pathogen Batrachochytrium dendrobatidis.

SWEETs represent a new class of sugar transporters first described in plants, animals, and humans and later in prokaryotes. Plant SWEETs play key roles in phloem loading, seed filling, and nectar secretion, whereas the role of archaeal, bacterial, and animal transporters remains elusive. Structural analyses show that eukaryotic SWEETs are composed of 2 triple-helix bundles (THBs) fused via an inversion linker helix, whereas prokaryotic SemiSWEETs contain only a single THB and require homodimerization to form transport pores. This study indicates that SWEETs retained sugar transport activity in all kingdoms of life, and that SemiSWEETs are likely their ancestral units. Fusion of oligomeric subunits into single polypeptides during evolution of eukaryotes is commonly found for transporters. Phylogenetic analyses indicate that THBs of eukaryotic SWEETs may not have evolved by tandem duplication of an open reading frame, but rather originated by fusion between an archaeal and a bacterial SemiSWEET, which potentially explains the asymmetry of eukaryotic SWEETs. Moreover, despite the ancient ancestry, SWEETs had not been identified in fungi or oomycetes. Here, we report the identification of SWEETs in oomycetes as well as SWEETs and a potential SemiSWEET in primitive fungi. BdSWEET1 and BdSWEET2 from Batrachochytrium dendrobatidis, a nonhyphal zoosporic fungus that causes global decline in amphibians, showed glucose and fructose transport activities.-Hu, Y.-B., Sosso, D., Qu, X.-Q., Chen, L.-Q., Ma, L., Chermak, D., Zhang, D.-C., Frommer, W. B. Phylogenetic evidence for a fusion of archaeal and bacterial SemiSWEETs to form eukaryotic SWEETs and identification of SWEET hexose transporters in the amphibian chytrid pathogen Batrachochytrium dendrobatidis.

[A Mononuclear Terbium(â ¢) Complex Constructed with 2,2'-Oxybis (benzoic acid) and 1,10-Phenanthroline: Fluorescence and Fluorescent Sensing for Fe3+ ion].

New complex [Tb(2,2'-oba)2(phen)2]-(H+3O) (2,2'-oba=2,2'-oxybis(benzoic acid), phen=1,10-phenanthroline) was synthesized under hydrothermal condition and characterized with X-ray single crystal diffraction. Complex reveals mononuclear structure containing TbO4N4 unit. Complex displays the emission peaks at 489，546，584 and 622 nm, corresponding to the 5D4→7FJ(J=6-3) transitions of Tb(Ⅲ) ion. The emission band at 546 nm corresponds to the 5D4→7F5 transition of the Tb(Ⅲ) ion, which gives an intense green luminescence output for the solid sample. The recognition for metal ions was discussed with fluorescent spectroscopy. The results show that it has high selectivity for Fe3+ via a fluorescence quenching mechanism. Luminescent investigations reveal that it can detect Fe3+ with relatively high sensitivity and selectivity, even when pH 4.0～8.0，which leads to its application in biotic and environmental system.

Nanobacteria may be linked to calcification in placenta.

AIMS: Placental calcification is a common pathologic condition in obstetrics. To detect the bacteria infection mechanisms for calcification, an experiment was performed to isolate, culture, and identify the nanobacteria in placental calcification. METHOD: Sixteen cases of placental calcification of pregnant women were collected for the purpose of the isolation of nanobacteria, cultivation, and identification of 16S rDNA sequence. RESULT: Under transmission electron microscope, novel oval-shape nanobacteria-like particles (NLP) in extracellular matrix of calcified placenta tissues were found with 50-500 nm in diameter, and among hydroxyapatite crystals aggregation existed. After about 4 weeks of culturing and isolating NLP from these calcified tissues, all calcified placental tissue samples and one adjacent tissue of calcified placental tissue samples showed white granular depositions, which were firmly attached to the bottom of the culture tubes and visible to the naked eyes. In the control group they could not be seen. After PCR was amplified a 1407-bp fragment was obtained and submitted to GenBank after sequencing with accession number JN029830. The 16S rDNA sequence homology between the isolation strain and strain nanobacteria (X98418) was 92% in GenBank. CONCLUSION: For the first time isolated, cultured, and identified nanobacteria in placental calcification indicated that nanobacteria infection is related to placental calcification.

Antibody responses to SARS-CoV-2 in patients with COVID-19.

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.

4-[2-(3-Methoxyphenyl)ethenyl]-N-methylpyridinium tetraphenylborate.

In the title compound, C(15)H(16)NO(+).C(24)H(20)B(-), the pyridinium ring of the cation makes a dihedral angle of 4.3 (2) degrees with the benzene ring. Each is rotated in the same direction with respect to the central C-CH=CH-C linkage, by 10.0 (2) and 7.8 (2) degrees , respectively. The anions have a slightly distorted tetrahedral geometry. The most interesting feature of the structure is that the anions form a honeycomb-like hexagonal structure down the b axis through C-H...pi interactions. The hexagon is constructed from six BPh(4)(-) anions. The cations interact in a head-to-tail fashion along [010], forming chains, and pack antiparallel inside the above honeycomb-like structure through C-H...pi interactions.

(5Z)-4-Amino-2-(4-hydroxyphenyl)-1H-imidazol-5(2H)-one oxime 3-oxide.

The title molecule, C(9)H(10)N(4)O(3), consists of benzene and imidazole rings which are almost perpendicular to each other. A hydroxyimino group is directly linked to the imidazole ring with a double C=N bond, which is the first example in this type of compound. The double bond may be a good location for the initiation of various reactions with a wide range of potential applications. In the crystal structure, there are pi-pi interactions between molecules related by a centre of symmetry, with the imidazole and benzene rings almost completely overlapped. The molecules are hydrogen bonded in each direction and form a three-dimensional hydrogen-bond network.

[Protective effects of recombinant SCR15-18 domain of human soluble complement receptor type 1 on myocardial ischemia and reperfusion injury].

OBJECTIVE: To investigate the protective effects of recombinant SCR15-18 domain of human soluble complement receptor type 1 (sCR1-SCR-15-18) in rats underwent myocardial ischemia and reperfusion (I/R). METHODS: Sprague-Dawley rats were randomly divided into three groups (n = 12 each group): sham (SO); 30 min ischemia/3h reperfusion (I/R) and I/R plus sCR1-SCR15-18 (15 mg/kg before I/R, sCR1). Serum LDH, CK and cardiac myeloperoxidase (MPO) activity were measured. Infarct size, myocardial histopathological changes and myocardial C3c were also compared among groups. RESULTS: Infarct size [(16.1 +/- 3.3)% vs. (22.9 +/- 3.0)%, infarct zone/left ventricular mass, P < 0. 05] and CK [(2532.5 +/- 597.1) U/L vs. (3400.9 +/- 534.9) U/L, P < 0. 05] and LDH [(5436.2 +/- 611.3) U/L vs. (6572.0 +/- 476.3) U/L, P < 0. 05] as well as MPO activity in infarct zone [(0.81 +/- 0.14) U/g vs. (1.12 +/- 0.13) U/g, P < 0.05] were significantly decreased post sCR1 compared to I/R group. sCR1 also significantly attenuated histological myocardial injury and reduced the deposition of C3c in infarct zone. CONCLUSION: sCR1-SCR15-18 protein exerts cardioprotective effects in this rat I/R model.

Cellular and molecular immunopathogenesis of ulcerative colitis.

Ulcerative colitis (UC) is an inflammatory disease of the rectal and colonic mucosa and seems to result from a complex series of interactions between susceptibility genes, the environment and the immune system. Various components of the mucosal immune system are implicated in the immunopathogenesis of UC. Evidence from animal models also suggests that an altered immune response to the commensal microflora of the host plays a central role in the development of UC. So in this review, we elucidate the cells and molecules which are implicated in the immunopathogenesis of the disease from four aspects: antigens in the intestine, dendritic cells, toll like receptors and NF-kappaB in the UC.

Accuracy of microRNAs for the diagnosis of hepatocellular carcinoma: A systematic review and meta-analysis.

Due to the high morbidity, mortality and late detection of hepatocellular carcinoma (HCC), it becomes a major public health challenge. MicroRNAs (miRNAs) have been reported to be aberrantly expressed in patients with HCC and thus may serve as potential diagnostic biomarkers. The aim of this study was to systematically assess the diagnostic accuracy of miRNAs as biomarkers for diagnosing HCC through a meta-analysis. Our results indicated that serum miRNAs had a relatively high diagnostic value for HCC diagnosis; the combination of serum α-fetoprotein (AFP) and miRNAs displayed a better diagnostic accuracy than using AFP or miRNAs alone; the combination of multiple miRNAs assay in serum had the highest diagnostic accuracy in HCC diagnosis based on the published data. In conclusion, our meta-analysis suggests that miRNAs, especially serum miRNAs, had a relatively high diagnostic value for HCC diagnosis, which can discriminate HCC from healthy subjects and those with chronic hepatitis and cirrhosis easily, and may serve as a novel, less-invasive screening tool.

Molecular evolution of the rice miR395 gene family.

MicroRNAs (miRNAs) are 20-22 nucleotide non-coding RNAs that play important roles in plant and animal development. They are usually processed from larger precursors that can form stem-loop structures. Among 20 miRNA families that are conserved between Arabidopsis and rice, the rice miR395 gene family was unique because it was organized into compact clusters that could be transcribed as one single transcript. We show here that in fact this family had four clusters of total 24 genes. Three of these clusters were segmental duplications. They contained miR395 genes of both 120 bp and 66 bp long. However, only the latter was repeatedly duplicated. The fourth cluster contained miR395 genes of two different sizes that could be the consequences of intergenic recombination of genes from the first three clusters. On each cluster, both 1-duplication and 2-duplication histories were observed based on the sequence similarity between miR395 genes, some of which were nearly identical suggesting a recent origin. This was supported by a miR395 locus survey among several species of the genus Oryza, where two clusters were only found in species with an AA genome, the genome of the cultivated rice. A comparative study of the genomic organization of Medicago truncatula miR395 gene family showed significant expansion of intergenic spaces indicating that the originally clustered genes were drifting away from each other. The diverse genomic organizations of a conserved microRNA gene family in different plant genomes indicated that this important negative gene regulation system has undergone dramatic tune-ups in plant genomes.

[Cloning and analysis of a new NBS-LRR resistance gene family in rice].

Sequence-based gene isolation has been a practical approach for plant resistance gene cloning. In this study, RS13, a cloned rice sequence with the NBS (nucleotide-binding site) domain of resistance genes, was used as a probe to screen a bacterial artificial chromosome (BAC) library of rice variety IR64,and four positive clones were obtained. Of them the clone 14E19 covered the other three clones and was sequenced through a shotgun approach. The whole sequence of the insert fragment of 14E19 was assembled into approximately 73 kb in length. Genes on the whole assembled sequence were predicted,and four genes encoding NBS and LRR (leucine-rich repeat) domains were found, named as NL-A, B, C and D respectively. For further analysis, another longer BAC clone,106P13, covering 14E19 on the same chromosome position was identified from a BAC library of IRBB56 which had the same genome background with IR64. Ten NL-homologous copies were discovered on the sequence of the BAC clone 106P13, and four copies were identical with those on 14E19. The similar homologous sequences were also found in the genomic sequences of Nipponbare,93-11 and Guangluai4. However, NL sequences were less homologous with the known NBS-LRR resistance genes. This result indicated that NL was a new NBS-LRR gene family and was composed of ten members at least. RT-PCR and cDNA screening displayed that NL-B expressed in a bacterial blight-resistant rice variety IRBB4, indicating the gene was possibly involved in resistance reactions.

MicroRNAs as biomarkers for hepatocellular carcinoma diagnosis and prognosis.

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world, and it is the second leading cause of cancer-related deaths. Despite improvements in HCC therapy, the overall survival rate is still very low because of the late detection of the tumors. Thus, early detection of HCC offers the best chance of survival for patients. MicroRNAs (miRNAs) are evolutionarily conserved small noncoding RNAs involved in the regulation of gene expression and protein translation. Many studies have shown that they played a very important role in cancer progresses and outcomes. The aberrant expression of miRNAs is common in various human malignancies and it modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNAs and HCC, several studies have demonstrated that the aberrant expression of specific miRNAs can be detected in HCC patients' serum and plasma or HCC cells and tissues, and miRNAs have shown great promise as diagnostic and prognostic markers for HCC. In the present review, we discussed the applications of miRNAs as biomarkers for HCC diagnosis and prognosis, and the association between miRNAs polymorphisms and the risk of HCC as well.

A systematic review and meta-analysis of diagnostic accuracy of serum 1,3-ß-D-glucan for invasive fungal infection: Focus on cutoff levels.

To assess the diagnostic accuracy of 1,3-ß-D-glucan (BDG) assay for diagnosing invasive fungal infections (IFI), we searched the Medline and Embase databases, and studies reporting the performance of BDG assays for the diagnosis of IFI were identified. Our analysis was mainly focused on the cutoff level. Meta-analysis was performed using conventional meta-analytical pooling and bivariate analysis. Our meta-analysis covered 28 individual studies, in which 896 out of 4214 patients were identified as IFI positive. The pooled sensitivity, specificity, diagnostic odds ratio, and area under the summary receiver operating characteristic (AUC-SROC) curve were 0.78 [95% confidence interval (CI), 0.75-0.81], 0.81 (95% CI, 0.80-0.83), 21.88 (95% CI, 12.62-37.93), and 0.8855, respectively. Subgroup analyses indicated that in cohort studies, the cutoff value of BDG at 80 pg/mL had the best diagnostic accuracy, whereas in case-control studies the cutoff value of 20 pg/mL had the best diagnostic accuracy; moreover, the AUC-SROC in cohort studies was lower than that in case-control studies. The cutoff value of 60 pg/mL has the best diagnostic accuracy with the European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria as a reference standard. The 60 pg/mL cutoff value has the best diagnostic accuracy with the Fungitell assay compared to the BDG detection assay. The cutoff value of 20 pg/mL has the best diagnostic accuracy with the Fungitec G-test assay, and the cutoff value of 11 pg/mL has the best diagnostic accuracy with the Wako assay. Serum BDG detection is highly accurate for diagnosing IFIs. As such, 60 pg/mL of BDG level can be used as the best cutoff value to distinguish patients with IFIs from patients without IFI (mainly due to Candida and Aspergillus).

Cytotoxicity and apoptosis induced by nanobacteria in human breast cancer cells.

BACKGROUND: The existing evidence that nanobacteria (NB) are closely associated with human disease is overwhelming. However, their potential toxicity against cancer cells has not yet been reported. The objective of this study was to investigate the cytotoxic effects of NB and nanohydroxyapatites (nHAPs) against human breast cancer cells and to elucidate the mechanisms of action underlying their cytotoxicity. METHODOLOGY/PRINCIPAL FINDINGS: NB were isolated from calcified placental tissue, and nHAPs were artificially synthesized. The viability of the MDA-MB-231 human breast cancer cell line was tested by using the Kit-8 cell counting kit assay. Apoptosis was examined by transmission electron microscopy and flow cytometry. The endocytosis of NB and nHAPs by MDA-MB-231 cells was initially confirmed by microscopy. Although both NB and nHAPs significantly decreased MDA-MB-231 cell viability and increased the population of apoptotic cells, NB were more potent than nHAPs. After 72 hours, NB also caused ultrastructural changes typical of apoptosis, such as chromatin condensation, nuclear fragmentation, nuclear dissolution, mitochondrial swelling, and the formation of apoptotic bodies. CONCLUSION/SIGNIFICANCE: In MDA-MB-231 human breast cancer cells, NB and nHAPs exerted cytotoxic effects that were associated with the induction of apoptosis. The effects exerted by NB were more potent than those induced by nHAPs. NB cytotoxicity probably emerged from toxic metabolites or protein components, rather than merely the hydroxyapatite shells. NB divided during culturing, and similar to cells undergoing binary fission, many NB particles were observed in culture by transmission electron microscopy, suggesting they are live microorganisms.

Isolation, cultivation and identification of nanobacteria from placental calcification.

OBJECTIVE: The etiology of placental calcification (PC) is lack of research. To detect the bacterial infection mechanisms for PC, the experiment of isolating, culturing and identifying the nanobacteria in PC was done. METHOD: The calcified placental tissues from 18 confirmed PC cases with normal placental tissue samples from 18 cases were studied by transmission electron microscopy (TEM), special nanobacterial culture methods, and identification of 16S rRNA sequence. RESULT: Under transmission electron microscope (TEM), Nanobacteria-like particles (NLP) in extra-cellular matrix (ECM) of calcified placental tissues were found, they were 50-500 nm in diameter, existed aggregation, among hydroxyapatite (HAP) crystals. Isolation and culture of NLP from the calcified tissues with methods described for nanobacteria were successful. All calcified placental tissue samples showed white granular deposition, which were firmly attached to the bottom of the culture tubes visible to the naked eyes. In the control group they could not be seen. According to 16S rRNA gene sequences analysis and was amplified adopting PCR and obtained 1407 bp fragment. Submit to GenBank after sequencing with accession number JN029830. CONCLUSION: Indicating that nanobacteria infection is related with placental calcification.

4-[2-(4-cyanophenyl)ethenyl]-N-methylpyridinium tetraphenylborate.

In the title compound, C(15)H(13)N(2)(+).C(24)H(20)B(-), the pyridyl ring of the cation makes a dihedral angle of 1.6 degrees with the benzene ring. Each is rotated in the same direction with respect to the central -C-CH=CH-C- linkage, by 3.8 and 5.3 degrees, respectively. The anions have a slightly distorted tetrahedral geometry. Molecular packing analysis was carried out using the packing energy portioning scheme in the program OPEC. Around each anion in the crystal structure there are eight anions, which interact with the central anion through C-H...pi interactions. The cations are hydrogen bonded in a head-to-tail fashion, forming chains along [101].

The effect of molecular planarity on crystal non-centrosymmetry in benzylidene-aniline derivatives.

In the title compound, N-(2-methoxyphenyl)-4-nitrobenzylideneamine, C(14)H(12)N(2)O(3), the two phenyl rings make a dihedral angle of 48.0 (2) degrees and the nitro group is at an angle of 6.5 (1) degrees with respect to its attached phenyl ring. In the crystal structure, molecules are related as centrosymmetric pairs through pi-pi interactions and are further connected through strong C[bond]H...O hydrogen bonds [C...O 3.4259 (17) A and C[bond]H...O 167 degrees ], forming molecular stacks along [100]. These stacks associate further through longer C[bond]H...O interactions, forming two-dimensional networks. In the c direction, there are only weak van der Waals interactions. The relationship between the molecular planarity and its centrosymmetry is also briefly described.

1-(4-Bromophenyl)-3-(4-methylphenyl)prop-2-en-1-one.

In the molecule of the title compound, C16H13BrO, the two benzene rings are rotated in opposite directions with respect to the central C-C=C-C part of the molecule. The phenone O atom deviates from the least-squares plane of the molecule by 0.300 (3) A. In the crystal structure, molecules are paired through C-H...pi interactions. The molecular pairs along [001] are hydrogen bonded through three translation-related co-operative hydrogen bonds in the 'bay area', forming molecular chains, which are further hydrogen bonded through C-H...Br weak interactions, forming (010) molecular layers. In the third direction, there are only weak van der Waals interactions. The co-operative hydrogen bonds in the 'bay area' are discussed briefly.

C-H...pi, pi-pi and C-H...Cl interactions in chloro-substituted Schiff bases and 4-chloro-N-[4-(dimethylamino)benzylidene]aniline.

Molecular packing analyses were carried out on 15 crystal data sets of chloro-substituted Schiff bases, including that of the title compound, C15H15ClN2. C-H...pi and pi-pi interactions play a major role in the molecular self-assembly in the crystal. The former interactions favor molecules assembling into a screw, with a non-centrosymmetric crystal structure. When the molecular dipole is small, pi-pi interactions favor a parallel, but not usually antiparallel, mode of packing. Weak C-H...X hydrogen bonds (X = Cl or Br) and X...X interactions seem to be a secondary driving force in packing. The title molecule takes the trans form and the two benzene rings are twisted around the central linkage in opposite directions. In the crystal structure, molecules interact through C-H...pi and pi-pi interactions, forming a 'dimer' and further forming double chains along [001]. The double chains are extended along [101] through C-H...Cl hydrogen bonds, forming double layers in (010). In the third direction, there are only ordinary, weaker, van der Waals interactions, which explains the crystal habit (i.e. thin plate).