ABSTRACT
Flexible photodetector shows great potential applications in intelligent wearable devices, health monitoring, and biological sensing. In this work, single crystal ß-tellurium nanowires were grown on flexible muscovite by molecular beam epitaxy, constructing high-density ordered nanomesh structure. The prepared photodetectors based on tellurium nanomesh exhibit excellent mechanical flexibility, fast response in a broad range from ultraviolet to near-infrared, and good photosensitivity. We found that the flexible photodetectors with Shottky contact drastically suppressed dark current, while the response speed was lowered in comparison to the devices with ohmic contact, as holes would take a long time to tunnel through the Shottky barrier between metal and p-type Te. Moreover, the photoresponse of flexible Shottky photodetectors can be modulated by piezoelectricity of tellurium, and pronounced photocurrent increase after bending many times. Under external stress, polarization charges could tune Shottky barrier height of the metal/tellurium, resulting in variation of photocurrent. This research not only explores the broadband photoresponse and piezoelectric effect of tellurium nanomesh, but also promotes the integration and development of broadband flexible optoelectronic devices.
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Objective: To investigate if microRNA (miR) -23a knockdown could attenuate angiotensin â ¡(Angâ ¡) induced cardiac hypertrophy by activating phosphatase and tensin homolog deleted on chromosome ten(PTEN) and AMP-activated protein kinase(AMPK) pathway. Methods: Rat H9c2 cells were cultured in DMEM high glucose medium and put in 5% CO(2) incubator at 37 â(normal group). After 48 hours of culture, H9c2 cells were stimulated with 10 nmol/L Angâ ¡ to establish cell hypertrophy model (Angâ ¡group). The H9c2 cells were inoculated in a 6-well cell culture plate and cultured in an incubator at 37 â. When the confluence degree of cell growth was about 70%, the cells were transfected with different reagents, and 24 hours after transfection, 10 nmol/L Angâ ¡ was used to interfere with the cells. The H9c2 cells were divided into different groups according to the reagents, namely Angâ ¡+anti-miR group(transfected with miR-23a inhibitor), Ang â ¡+NC group(transfected with miR-23a inhibitor negative control), Ang â ¡+anti-miR+si-PTEN group(cotransfected with miR-23a inhibitor and PTEN small interference RNA(siRNA)), and Angâ ¡+anti-miR+si-NC group(cotransfected with miR-23a inhibitor and PTEN siRNA negative control). The surface area of single cell was measured by Image J software.The mRNA expression levels of α-actin 1 (ACTA1) and ß-myosin heavy chain (ß-MHC) and miR-23a were detected by quantitative real-time PCR(qRT-PCR). The expression levels of PTEN and AMPK signal pathway related proteins were detected by Western blot. In order to verify whether miR-23a targets PTEN gene, double luciferase reporter gene experiment was performed. The luciferase reporter gene vector recombinant plasmids of wild type pGL-WT-PTEN and mutant pGL-MUT-PTEN were constructed and prepared after normal sequencing. H9c2 cells was inoculated into 24-well cell culture plate and cultured overnight in 37 â incubator. The cells were co-transfected with miR-23a mimic or miR-23a mimic negative control and wild type or mutant reporter gene recombinant plasmid. Forty-eight hours after transfection, firefly luciferase activity and sea kidney luciferase activity were measured, and the ratio of them was recorded as relative luciferase activity. Results: Compared with the normal group, the cell surface area, the mRNA expression levels of ACTA1, ß-MHC and miR-23a were significantly higher, while the protein expression levels of PTEN and p-AMPK were significantly lower in the Ang â ¡ group(all P<0.05). The results of double luciferase reporter gene assay showed that the relative luciferase activity of cells co-transfected with miR-23a mimic and wild-type reporter gene recombinant plasmid was lower than that of miR-23a mimic negative control (P<0.05), and PTEN served as the target gene of miR-23a. In Angâ ¡+anti-miR group the mRNA expression levels of miR-23a, ACTA1 and ß-MHC were lower, and the cell surface area was smaller, while the protein expression levels of PTEN and p-AMPK were higher than that in Angâ ¡ group and Angâ ¡+NC group(all P<0.05). Compared with Angâ ¡+anti-miR group, the cell surface area was bigger, the expression of ACTA1 and ß-MHC mRNA was up-regulated, and the protein expression levels of PTEN and p-AMPK were down-regulated in Ang â ¡+anti-miR+si-PTEN group(all P<0.05). Conclusion: Inhibition of miR-23a can attenuate Ang â ¡-induced hypertrophy in H9c2 cells through targeting PTEN and activating AMPK signaling pathway.
Subject(s)
MicroRNAs/genetics , AMP-Activated Protein Kinases , Angiotensin II , Animals , Cardiomegaly , Cell Line , Cell Proliferation , PTEN Phosphohydrolase , Rats , Signal TransductionABSTRACT
The linear scaling or O(N) methods, which exhibit linear scaling with respect to the size of system, are a powerful tool for theoretically treating a huge system containing many atoms. We present a new linear scaling algorithm for large-scale tight-binding molecular dynamics simulations based on the divide-and-conquer approach, in which a system is divided into subsystems and each subsystem is calculated separately. Different from the common realization of the divide-and-conquer approach, our proposed method avoids building the density matrix or electronic density and gives a new strategy to access the physical properties of a large system. We apply this method to the tungsten metallic system and show that this method very effectively yields the same results including the atomic structures, the melting point, the formation energy of defects, and the electronic properties as those obtained from the exact diagonalization of tight-binding Hamiltonian matrix of a whole system. This method has the advantages of linear scaling complexity, less memory consumption, and high parallel efficiency, which make it to be used for the large-scale simulations.
ABSTRACT
Warm dense conditions in titanium foils irradiated with intense femtosecond laser pulses are diagnosed using an x-ray imaging spectroscopy technique. The line shapes of radially resolved titanium Kα spectra are measured with a toroidally bent GaAs crystal and an x-ray charge-coupled device. Measured spectra are compared with the K-shell emissions modeled using an atomic kinetics - spectroscopy simulation code. Kα line shapes are strongly affected by warm (5-40 eV) bulk electron temperatures and imply multiple temperature distributions in the targets. The spatial distribution of temperature is dependent on the target thickness, and a thin target shows an advantage to generate uniform warm dense conditions in a large area.
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Human papillomavirus (HPV) is an infection that can be sexually transmitted and result in health consequences. Persistent high-risk HPV infection can lead to various cancers and is the essential cause of cervical cancer. HPV vaccine can prevent the HPV infection and thus the incidence of cervical cancer. In this review we introduced the prevalence of HPV infection and vaccination, and the prevention and early detection of cervical cancer. We also introduced the present knowledge and awareness of HPV infection and HPV vaccine in Chinese. Propaganda all over China should be performed on HPV vaccination to improve the vaccination rate, thus preventing the incidence of cervical cancer.
Subject(s)
Papillomavirus Infections/prevention & control , Papillomavirus Vaccines , China/epidemiology , Female , Humans , Incidence , Papillomaviridae , Papillomavirus Infections/epidemiology , Prevalence , Uterine Cervical Neoplasms/prevention & control , Uterine Cervical Neoplasms/virology , VaccinationABSTRACT
We apply active feedback optimization methods to pyroelectric measurements of a THz signal generated by four wave mixing in air using 1 mJ to 12 mJ, 35 fs laser pulses operating at 12 kHz repetition rate. A genetic algorithm, using the THz signal as a figure of merit, determines the voltage settings to a deformable mirror and results in up to a 6 fold improvement in the THz signal compared with settings optimized for the best focus. It is possible to optimize for different THz generation processes using this technique.
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BACKGROUND: The current evidence implicates that psychosocial stress, especially pregnancy-specific stress, is associated with the risk of spontaneous preterm birth. The aim of the present study was to determine the effect of pregnancy-specific stress on spontaneous preterm birth among Chinese people. MATERIALS AND METHODS: A total of 2,189 pregnant women were enrolled and followed up until parturition from February 2011 to January 2012. Maternal pregnancy-specific stress was assessed using the revised Pregnancy Stress Rating Scale (PSRS) at third trimester in pregnancy. Socio-demographic and psychological data were collected through interviews, medical, and obstetrical examination records. RESULTS: High levels of maternal pregnancy-specific stress during the third trimester increased risk of spontaneous preterm birth compared with the low and medium levels (adjusted risk ratios, 2.92; 95% confidence interval, 1.12-7.58). The first stressor from the revised PSRS includes a risk factor for the safety of infants. CONCLUSIONS: High level of pregnancy-specific stress in third trimester might predict spontaneous preterm birth.
Subject(s)
Pregnancy Complications , Pregnancy Trimester, Third , Premature Birth/epidemiology , Stress, Psychological/complications , Adult , China/epidemiology , Female , Humans , Incidence , Infant, Newborn , Odds Ratio , Pregnancy , Premature Birth/etiology , Risk Factors , Young AdultABSTRACT
This study aims to examine the association between proliferator-activated receptor γ (PGC)-gene family-related single nucleotide polymorphisms (SNPs) and elite endurance runners' status in a Chinese cohort, and to gain insights into the functionality of a subset of SNPs. Genotype distributions of 133 SNPs in PPARGC1A, PPARGC1B, PPRC1, TFAM, TFB1M, TFB2M, NRF1, GABPA, GABPB1, ERRα, and SIRT1 genes were compared between 235 elite Chinese (Han) endurance runners (127 women) and 504 healthy non-athletic controls (237 women). Luciferase gene reporter activity was determined in 20 SNPs. After adjusting for multiple comparisons (in which threshold P-value was set at 0.00041), no significant differences were found in allele/genotype frequencies between athletes and controls (when both sexes were analyzed either together or separately). The lowest P-value was found in PPARGC1A rs4697425 (P = 0.001 for the comparison of allele frequencies between elite female endurance runners and their gender-matched controls). However, no association (all P > 0.05) was observed for this SNP in a replication cohort from Poland (194 endurance athletes and 190 controls). Using functional genomics tool, the following SNPs were found to have functional significance: PPARGC1A rs6821591, rs12650562, rs12374310, rs4697425, rs13113110, and rs4452416; PPARGC1B rs251466 and rs17110586; and PPRC1 rs17114388 (all P < 0.001). This study found no significant association between PGC-related SNPs and elite endurance athlete status in the Chinese population, despite some SNPs showing potential functional significance and the strong biological rationale to hypothesize that this gene pathway is a candidate to influence endurance exercise capacity.
Subject(s)
PPAR gamma/genetics , Physical Endurance/genetics , Polymorphism, Single Nucleotide , Running/physiology , Transcription Factors/genetics , Adult , Asian People , Carrier Proteins/genetics , Case-Control Studies , China , Cohort Studies , DNA-Binding Proteins/genetics , Female , GA-Binding Protein Transcription Factor/genetics , Gene Frequency , Genotype , Humans , Male , Methyltransferases/genetics , Mitochondrial Proteins/genetics , Nuclear Respiratory Factor 1/genetics , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha , Poland , RNA-Binding Proteins , Receptors, Estrogen/genetics , Sirtuin 1/genetics , Spain , ERRalpha Estrogen-Related ReceptorABSTRACT
As lasers become progressively higher in power, optical damage thresholds will become a limiting factor. Using the nonlinear optics of plasma may be a way to circumvent these limits. Here, we present a new self-compression mechanism for high-power, femtosecond laser pulses based on geometrical focusing and three dimensional spatiotemporal reshaping in an ionizing plasma. By propagating tightly focused, 10-mJ femtosecond laser pulses through a 100-µm gas jet, the interplay between ionization gradients, focusing, and diffraction of the light pulse leads to stable and uniform self-compression of the pulse, while maintaining a high-energy throughput and excellent refocusability. Self-compression down to 16 fs from an original 36-fs pulse is measured using second-harmonic-generation frequency-resolved optical gating. Using this mechanism, we are able to maintain a high transmission (>88%) such that the pulse peak power is doubled. Three-dimensional numerical simulations are performed to support our interpretation of the experimental observations.
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Stripe rust is a major fungal disease of wheat. It frequently becomes epidemic in southeastern Gansu province, a stripe rust hot spot in China. Evaluations of wheat germplasm response are crucial for developing cultivars to control the disease. In total, 57 wheat cultivars and lines from Europe and other countries, comprising 36 cultivars with documented stripe rust resistance genes and 21 with unknown genes, were tested annually with multiple races of Puccinia striiformis f. sp. tritici in the field at Tianshui in Gansu province from 1993 to 2013. Seven wheat lines were highly resistant, with infection type (IT) 0 during the entire period; 16 were moderately resistant (IT 0;-2); and 26 were moderately susceptible (IT 0;-4), with low maximum disease severity compared with the susceptible control Huixianhong. 'Strampelli' and 'Libellula', with three and five quantitative trait loci, respectively, for stripe rust resistance have displayed durable resistance in this region for four decades. Ten cultivars, including 'Lantian 15', 'Lantian 26', and 'Lantian 31', with stripe rust resistance derived from European lines, were developed in our breeding program and have made a significant impact on controlling stripe rust in southeastern Gansu. Breeding resistant cultivars with multiple adult-plant resistance genes seems to be a promising strategy in wheat breeding for managing stripe rust in this region and other hot spots.
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In this study, we examined the changes in the fibrinolytic system in a rabbit model of two acute pulmonary thromboembolisms (PTE). Fourteen healthy adult New Zealand white rabbits were divided into three groups: the single PTE group (five rabbits), the double PTE group (five rabbits), and the control group (four rabbits). A rabbit model of acute pulmonary embolism was established, and immunohistochemistry and polymerase chain reaction (PCR) were performed on tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) in plasma, and pulmonary embolism tissue. Plasma results: 1) t-PA levels: one hour following the initial modeling, the levels of t-PA in the modeling groups were significantly lower than those in the control group (P<0.05). In addition, the t-PA levels in the double PTE group were found to be lower after the modeling, as compared to the pre-modeling period (P<0.05). One hour after the second modeling, the double PTE group had lower t-PA levels compared to the control group (P<0.05). However, t-PA rebounded two hours after modeling in the double PTE group. One week after the second modeling, the double PTE group had higher t-PA levels compared to the other two groups (P<0.05). 2) PAI-1 results: one hour after the initial modeling, PAI-1 levels in the two modeling groups were lower compared to the pre-modeling period and control groups (P<0.05). Two hours following modeling, PAI-1 levels in both modeling groups were lower compared to the control group (P<0.05). PAI-1 levels were lower in the double PTE group one and two hours after the second modeling compared to the other two groups and pre-modeling period (P<0.05). 3) The immunohistochemistry results: the expression of PAI-1 decreased in the two modeling groups, while t-PA expression increased compared to the control group. 4) PCR results: t-PA mRNA expression did not differ among the three groups. The PAI-1 mRNA expression was lower in the two PTE groups compared to the control group. We conclude that in the early stages of PTE, the local fibrinolytic activity of the thrombus is increased, which is favorable for thrombolysis. However, as the thrombus persists, the activity of the fibrinolytic system is inhibited, contributing to the development of chronic thromboembolic pulmonary hypertension.
Subject(s)
Disease Models, Animal , Fibrinolysis , Plasminogen Activator Inhibitor 1 , Pulmonary Embolism , Tissue Plasminogen Activator , Animals , Rabbits , Pulmonary Embolism/metabolism , Pulmonary Embolism/blood , Pulmonary Embolism/pathology , Plasminogen Activator Inhibitor 1/metabolism , Plasminogen Activator Inhibitor 1/genetics , Tissue Plasminogen Activator/metabolism , Tissue Plasminogen Activator/genetics , Male , RNA, Messenger/metabolism , RNA, Messenger/genetics , Lung/metabolismABSTRACT
The generation of ultrarelativistic positron beams with short duration (τ(e+) ≃ 30 fs), small divergence (θ(e+) ≃ 3 mrad), and high density (n(e+) ≃ 10(14)-10(15) cm(-3)) from a fully optical setup is reported. The detected positron beam propagates with a high-density electron beam and γ rays of similar spectral shape and peak energy, thus closely resembling the structure of an astrophysical leptonic jet. It is envisaged that this experimental evidence, besides the intrinsic relevance to laser-driven particle acceleration, may open the pathway for the small-scale study of astrophysical leptonic jets in the laboratory.
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Over thirty publications during the last 10 years have identified more than 140 QTLs for stripe rust resistance in wheat. It is likely that many of these QTLs are identical genes that have been spread through plant breeding into diverse backgrounds through phenotypic selection under stripe rust epidemics. Allelism testing can be used to differentiate genes in similar locations but in different genetic backgrounds; however, this is problematic for QTL studies where multiple loci segregate from any one parent. This review utilizes consensus maps to illustrate important genomic regions that have had effects against stripe rust in wheat, and although this methodology cannot distinguish alleles from closely linked genes, it does highlight the extent of genetic diversity for this trait and identifies the most valuable loci and the parents possessing them for utilization in breeding programs. With the advent of cheaper, high throughput genotyping technologies, it is envisioned that there will be many more publications in the near future describing ever more QTLs. This review sets the scene for the coming influx of data and will quickly enable researchers to identify new loci in their given populations.
Subject(s)
Basidiomycota/physiology , Disease Resistance/immunology , Plant Diseases/microbiology , Quantitative Trait Loci/genetics , Triticum/genetics , Triticum/microbiology , Chromosome Mapping , Disease Resistance/genetics , Plant Diseases/genetics , Plant Diseases/immunology , Triticum/immunologyABSTRACT
BACKGROUND: Familial combined hyperlipidemia (FCHL) is the most commonly inherited hyperlipidemia in men. It constitutes a substantial risk factor for atherosclerosis patients. AIM: To delineating the potential mechanism of FCHL by bioinformatics tools. MATERIALS AND METHODS: In this study, Protein-Protein Interaction (PPI) network was constructed to identify the potential functional proteins and their interactive relationships in familial combined hyperlipidemia. RESULTS: Our results showed that androgen receptor (AR) might play an important role in familial combined hyperlipidemia by interaction with TGIF1, NR3C1, KLK2, etc. Some pathways were also identified, such as Hedgehog signaling pathway, Phosphatidylinositol signaling system, and Long-term depression, which were all demonstrated participating in lipid metabolism in previous experiments. CONCLUSIONS: Although lack of direct evidence, by PPI network construction it proved AR is a key factor in FCHL, and also demonstrated that PPI network construction is an alternative avenue for FCHL analysis.
Subject(s)
Hyperlipidemia, Familial Combined/physiopathology , Algorithms , Databases, Genetic , Gene Expression , Humans , Hyperlipidemia, Familial Combined/genetics , Microarray Analysis , Signal Transduction/physiologyABSTRACT
Objective: To explore the mechanism of intestinal tissue damage induced by macrophages activated by WNT2B high-expressed fibroblasts. Methods: This study involved biological information analysis, pathological tissue research and cell experimental research. The biological information of the colon tissue from the children with inflammatory bowel disease in previous study was analyzed again with single-cell sequencing. The pathological tissues were collected by colonoscopy from 10 children with Crohn's disease treated in the Department of Gastroenterology of Guangzhou Women and Children's Medical Center from July 2022 to September 2022. According to the findings of colonoscopy, tissues with obvious inflammation or ulceration were classified as the inflammatory group, while tissues with slight inflammation and no ulceration were classified as the non-inflammatory group. HE staining was performed to observe the pathological changes of the colon tissues. Macrophage infiltration and CXCL12 expression were detected by immunofluorescence. In terms of cell experiments, fibroblasts transfected with WNT2B plasmid or empty plasmid were co-cultured with salinomycin treated or non-treated macrophages, respectively; the expression of proteins through Wnt classical pathway were detected by western blotting. Macrophages treated with SKL2001 were used as the experimental group, and those with phosphate buffer as the control group. The expression and secretion of CXCL12 in macrophages were detected by quantitative Real-time PCR and enzyme-linked immunosorbent assay (ELISA). T-test or rank sum test were used for the comparison between groups. Results: Single-cell sequencing analysis suggested that macrophages were the main cells in inflammatory bowel disease colon tissue, and there was interaction between WNT2B high-expressed fibroblasts and macrophages. HE staining of the 10 patients ((9.3±3.8) years old, 7 males and 3 females) showed that the pathological score of colon tissue in the inflammatory group was higher than that in the non-inflammatory group (4 (3, 4) vs. 2 (1, 2) points, Z=3.05, P=0.002). Tissue immunofluorescence indicated that the number of infiltrating macrophages in the inflammatory group was significantly higher than that in the non-inflammatory group under high power field of view (72.8±10.4 vs.8.4±3.5, t=25.10, P<0.001), as well as the number of cells expressing CXCL12 (14.0±3.5 vs. 4.7±1.9, t=14.68, P<0.001). In cell experiments, western blotting suggested an elevated level of glycogen synthase kinase-3ß phosphorylation in macrophages co-cultured with fibroblast transfected with WNT2B plasmid, and salinmycin could reverse this change. Real-time PCR suggested that the transcription level of CXCL12 in the experimental group was higher than that in the control group (6.42±0.04 vs. 1.00±0.03, t=183.00, P<0.001), as well as the expression and secretion of CXCL12 by ELISA ((465±34) vs. (77±9) ng/L, t=13.21, P=0.006). Conclusion: WNT2B high-expressed fibroblasts can secrete WNT2B protein and activate the Wnt classical signaling pathway thus enhancing the expression and secretion of CXCL12 in macrophages, inducing the development of intestinal inflammation of Crohn's disease.
Subject(s)
Crohn Disease , Inflammatory Bowel Diseases , Child , Male , Humans , Female , Child, Preschool , Adolescent , Colon , Inflammation , Colonoscopy , Glycoproteins , Wnt ProteinsABSTRACT
To explore the effectiveness of modified inversion-polymerase chain reaction (I-PCR) to detect the factor VIII (FVIII) intron 22 inversion (Inv22) for genetic diagnosis and prenatal diagnosis in haemophilia A (HA). Both modified I-PCR and LD-PCR were applied to analyse the FVIII Inv22 for 24 patients with HA. Prenatal diagnosis was performed on six foetuses. Foetal blood samplings were carried out by cordocentesis from 22 to 26 weeks of gestation. Ten patients with FVIII Inv22 in 10 HA families were found, and the remaining 14 patients were found without the Inv22 in 19 HA families. Prenatal diagnosis confirmed that four foetuses were normal and all of them born normally. However, two foetuses had been identified as abnormal and undergone abortion. Compared with LD-PCR, modified I-PCR is more rapid and convenient for detecting the FVIII Inv22 in genetic diagnosis. It is recommended that a patient undergoes both modified I-PCR (to detect the FVIII Inv22) and biochemical assay (to measure the FVIII activity of umbilical cord blood) in prenatal diagnosis. When we have more experience, the DNA samples from chorionic villus or amniotic fluid can be analysed for prenatal diagnosis using the modified I-PCR alone.
Subject(s)
Chromosome Inversion/genetics , Factor VIII/genetics , Hemophilia A/diagnosis , Introns/genetics , Polymerase Chain Reaction/methods , Prenatal Diagnosis/methods , China , Female , Hemophilia A/genetics , Humans , PregnancyABSTRACT
Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common parasitic infections in humans. Primary infection in pregnant women can be transmitted to the fetus leading to miscarriage or congenital toxoplasmosis. Carefully designed nationwide seroprevalence surveys and case-control studies of risk factors conducted primarily in Europe and America, have shaped our view of the global status of maternal and congenital infection, directing approaches to disease prevention. However, despite encompassing 1 in 5 of the world's population, information is limited on the status of toxoplasmosis in China, partly due to the linguistic inaccessibility of the Chinese literature to the global scientific community. By selection and analysis of studies and data, reported within the last 2 decades in China, this review summarizes and renders accessible a large body of Chinese and other literature and aims to estimate the seroprevalence in Chinese pregnant women. It also reviews the prevalence trends, risk factors, and clinical manifestations. The key findings are (1) the majority of studies show that the overall seroprevalence in Chinese pregnant women is less than 10%, considerably lower than a recently published global analysis; and (2) the few available appropriate studies on maternal acute infection suggested an incidence of 0·3% which is broadly comparable to studies from other countries.
Subject(s)
Toxoplasma , Toxoplasmosis/blood , Toxoplasmosis/epidemiology , China/epidemiology , Female , Humans , Pregnancy , Risk Factors , Seroepidemiologic Studies , Toxoplasmosis/pathologyABSTRACT
In October 2010, a Colletotrichum species was isolated from white Phalaenopsis flowers growing in a greenhouse in San Francisco, CA. This Phalaenopsis is a common commercial orchid hybrid generated mostly likely from Phalaenopsis amabilis and P. aphrodite. The white petals showed anthracnose-like lesions where necrotic tissue is surrounded by a ring of green tissue. The green halo tissues around the necrotic tissue contain functional chloroplasts. One-centimeter disks were cut around the necrotic sites and surface-sterilized with 95% ethanol and 0.6% sodium hypochlorite. The disks were placed on potato dextrose agar (PDA) medium to establish cultures. Pure cultures were obtained by subculturing hyphal tips onto fresh PDA plates. The generated colonies had white aerial mycelia and orange conidial mass. The color of the reverse colony varies between colorless and pale orange. Microscopic observations identified the conidia as cylindrical, straight, and rounded at both ends. In addition, the conidia were approximately 15.0 to 18.0 µm long and 5.0 to 6.5 µm in diameter. These observed morphological features suggested that these isolates possessed the same characteristics as previously described for Colletotrichum karstii, a species considered as part of the C. boninense species complex (1). Four putative independent Colletotrichum isolates were recovered (DED9596, DED9597, DED9598, and DED9599). To confirm the Colletotrichum isolates as the causative pathogen, healthy white Phalaenopsis flowers (five total) in a whole plant were sprayed with a conidial suspension (approximately 1.2 × 106 conidia/ml) of the isolates and incubated at 20°C and 100% relative humidity with cycles of 16 h light and 8 h of darkness. Approximately 1 ml of conidial suspension solution was used for each flower. The plants were watered regularly and flowers were sprayed with sterile double-distilled water daily. As negative controls, five flowers in a whole plant were sprayed with water. Fifteen to twenty days after inoculation, lesions started to form on the petals sprayed with the putative Colletotrichum isolates. All controls remained healthy. The Colletotrichum-inoculated flowers remained alive and did not die as a result of the infection. This same experiment was repeated and the same results were obtained. DNA was extracted from the necrotic regions of the petals infected by the pure cultures of the four isolates and used to sequence the 18S rRNA ITS (internal transcribed spacer) region. All four isolates gave identical ITS sequences. Analysis of the obtained representative sequences (GenBank Accession No. JQ277352) suggested that the isolated pathogen as C. karstii. Using the published ITS data for the C. boninense species complex (1), a phylogenetic tree was generated via the maximum likelihood method. This created tree places the isolates in the same group as C. karstii. This type of C. karstii infection in Phalaenopsis orchid petals was not documented in the U.S. before, although it has been reported in China and Thailand (2). To our knowledge, this is the first report of infection and green island formation caused by C. karstii on orchid flower in the United States. References: (1) Damm et al. Studies in Mycology 73:1, 2012. (2) Yang et al. Cryptogamie Mycologie 32:229, 2011.
ABSTRACT
The purposes of this study were to investigate the distribution characteristics of CAG repeat polymorphism in exon 1 of androgen receptor gene and the association of CAG polymorphism with VO2max response to hypoxic training in North China Han men. Sixty-five healthy young men completed a 30-day HiHiLo training (living high, exercise high and training low) in a simulated normobaric hypoxic environment. All subjects slept in 14.3-14.8% O2 concentration, and participated in hypoxic training three times a week in 15.4% O2 concentration. VO2max (peak oxygen consumption) and body weight were measured before and after hypoxic training. A total of 15 repeat alleles were observed by CAG genotype analyze, in which (CAG)22 was most common. When using 21 and 22 alleles, respectively, as cut-off points, we found that the baseline body weight of two shorter genotype groups was significantly lower than that of longer ones, and that the ΔVO2max and ΔrVO2max (Δrelative value of VO2max) of two shorter genotype groups were significantly higher than those of longer ones after hypoxic training. These findings indicated that AR CAG repeat polymorphism was associated with the exercise performance after simulated normobaric hypoxic HiHiLo training in North China Han men, and that the shorter genotypes had a better individual response to hypoxic training.