Survey of infection and determination of the transmission vector of Onchocerca fasciata in camels (Camelus bactrianus) in Inner Mongolia, China.

Onchocerciasis in camels is caused by adult Onchocerca spp. and results in great economic losses to the camel industry. However, only a few studies on Onchocerca have been conducted, especially regarding the intermediate host and vector(s). In the present study, 192 camels were examined from December and January during 2013 and 2016, and the filarial larvae suspected to be Onchocerca spp. were further identified. Furthermore, aquatic dipteran insects in the living environment of camels were collected from May to September between 2013 and 2017 and dissected. Eventually, onchocercal lesions were observed in 95 of 192 (49%) camels and the captured insects were classified into 49 species from 42 genera in 21 families, among which 18 species were newly recorded in Inner Mongolia and 14 were haematophagous species. The filarial larvae were found in Culicoides puncticollis and identified as Onchocerca fasciata, indicating that C. puncticollis is the vector of O. fasciata in Inner Mongolia. These findings provide an estimate of onchocerciasis infection in camels and an alternative method of identifying insects and screening vectors using molecular methods. Important data are also provided for the diagnosis and control of onchocerciasis, thereby further filling the gap in knowledge regarding transmission vectors in China.

[Epidemiological characteristics of pneumoconiosis in Gansu Province from 2010 to 2018].

Objective: The epidemiological characteristics of occupational pneumoconiosis in Gansu Province from 2010 to 2018 were analyzed to provide a theoretical basis for the development of prevention and control strategies for pneumoconiosis in Gansu Province. Methods: In March 2019, the data of newly diagnosed occupational pneumoconiosis in 2010-2018 and the data of occupational pneumoconiosis as of December 31, 2018 in Gansu Province were collected by the Occupational Disease and Occupational Health Information Monitoring System. The stage, type of disease, time, enterprise information of newly diagnosed pneumoconiosis and the region, type of disease, enterprise information of existed pneumoconiosis were analyzed. Results: From 2010 to 2018, a total of 1269 new cases of occupational pneumoconiosis were reported in Gansu Province, including 818 cases (64.46%) of stage I pneumoconiosis, 284 cases (22.38%) of stage II pneumoconiosis, 167 cases (13.16%) of stage III pneumoconiosis. Silicosis, coal worker's pneumoconiosis and cement pneumoconiosis ranks the top 3, accounting for 55.71% (707/1269) , 37.67% (478/1269) and 3.78% (48/1269) of the total number, respectively. The new cases of stage III pneumoconiosis were mainly distributed in private economy (58.09%, 79/136) and small-sized (59.88%, 97/162) enterprises. As of December 31, 2018, Gansu Province had reported a total of 12211 cases of occupational pneumoconiosis, of which 58.16% (7102/12211) were coal worker's pneumoconiosis and 28.15% (3438/12211) were silicosis. Mainly distributed in Baiyin city (21.63%, 2641/12211) , Lanzhou city (17.79%, 2172/12211) and Wuwei city (13.73%, 1676/12211) . The existed cases of pneumoconiosis are mainly distributed in state-owned economy (76.95%, 9396/12211) and large-sized (54.23%, 6622/12211) enterprises. Conclusion: Silicosis and coal worker's pneumoconiosis are the main type of pneumoconiosis in Gansu Province. And the number of silicosis reported is on the rise, which should be taken seriously. Pneumoconiosis in Gansu Province is mainly distributed in state-owned economy and large-sized enterprises. However, pneumoconiosis patients in private economy and small-sized enterprise is generally serious, so it should be the focus of supervision.

Observation of incoherently coupled dark-bright vector solitons in single-mode fibers.

We report experimental observation of incoherently coupled dark-bright vector solitons in single-mode fibers. Properties of the vector solitons accord well with those predicted by the respective systems of incoherently coupled nonlinear Schrödinger equations. To our knowledge, this is the first experimental observation of temporal incoherently coupled dark-bright solitons in single-mode fibers.

Observation of dark-bright vector solitons in fiber lasers.

We report the experimental observation of coherently coupled dark-bright vector solitons in single mode fiber lasers with either normal or anomalous cavity dispersion. The properties of these vector solitons were found to agree well with theoretical predictions based on the coherently coupled nonlinear Schrödinger equations. The experimental results clearly confirmed the existence of a fundamentally new form of optical solitons in coupled nonlinear systems.

[Epidemiological study of occupational diseases in Gansu province, China in 2010-2017].

Objective: To analyze the epidemiological characteristics of occupational diseases in Gansu Province, China in 2010-2017, and to provide a scientific basis for the prevention and control of occupational diseases. Methods: The cluster sampling method was adopted to make statistical analysis of 1339 cases of occupational disease reported by "occupational disease and occupational health information monitoring system" in Gansu province from 2010 to 2017, to investigate the diseases, regions and industries of occupational diseases in June 2018. Results: A total of 1339 cases of occupational diseases (39 types, 8 classes) were diagnosed and reposed in 2010-2017. The three most frequent diseases were pneumoconiosis (87.53%, 1172/1339), occupational poisonings (5.83%, 78/1339), and occupational ear, nose, and throat (ENT) diseases (3.14%, 42/1339). The cases of silicosis accounted for 54.61% (640/1172) of all cases of pneumoconiosis, the second was coalworker pneumoconiosis, which accounted for 38.57% (452/1172). In the cases of occupational poisonings, 32.05% (25/78) suffered from carbon monoxide poisoning. Patients with occupational diseases were reported in 14 districts of Gansu, mostly in Lanzhou (27.52%, 347/1261), Jinchang (16.57%, 209/1261), and Baiyin (14.20%, 179/1261). The reported cases are mainly concentrated in mining (71.56%, 468/654) and manufacturing (21.87%, 143/654), the types of state-owned economy (55.63%, 692/1244) and private economy (33.68%, 419/1244), large (43.41%, 540/1244) and small enterprises (35.21%, 438/1244) in 2010-2017 in Gansu. Conclusion: The pneumoconiosis caused by silicious and coal dust and the occupational poisonings caused by carbon monoxide seem to be the main occupational hazards in Gansu province. Occupational diseases occur in all districts of Guangzhou and in various industries. The state-owned economy and private sector, large and small enterprises should be the focuses of occupational health supervision.

[YAP regulates the proliferation and modifies the sensitivity to sorafenib in hepatocellular carcinoma cells].

Objective: To detect the expression level of YES-associated protein 1 (YAP) in hepatocellular carcinoma (HCC) cell lines and investigate its effects on the proliferation activity and the sensitivity to sorafenib in HCC cells. Methods: Western blot was used to detect the protein expression levels of YAP in SMMC-7721, SK-Hep-1, HepG-2, Huh7 and the normal liver cell line L-O2. YAP specific small interfering RNA (si-YAP) or YAP expression plasmid were transfected in SK-Hep-1 or Huh7 cells, respectively. Cell counting kit-8 (CCK-8) test was used to detect the cell proliferation activity and the cell cycle test was conducted by flow cytometry. SK-Hep-1 and SK-Hep-1 si-YAP cells were subcutaneously injected into the nude mice which were sequentially treated by intragastric administration of sorafenib, and the tumor growth in vivo were observed and compared. Results: The expression of YAP was upregulated in HCC cell lines. Deletion of YAP expression significantly decreased the survival rate of SK-Hep-1 cells [(78.5±0.3)% vs (92.3±0.2)%, P=0.025]. Knockdown of YAP significantly increased the percentage of G(0)/G(1)-phase cells [ (65.4±3.3) % vs (55.7±3.4) %, P=0.039]. On the contrary, upregulation of the YAP expression in Huh7 cells significantly increased the cell survival rate [(81.2±1.3)% vs (62.5±1.1)%, P=0.013] and reduced the percentage of G(0)/G(1)-phase cells [(38.2±3.8)% vs (48.8±2.9)%, P=0.019]. The survival rate of SK-Hep-1 cells treated by si-YAP combined with sorafenib was (31.13±1.79)%, significantly lower than (48.87±0.58) % of SK-Hep-1 cells treated by sorafenib alone (P=0.001), while overexpression of YAP attenuated the inhibitory effect of sorafenib on the survival of Huh7 cells [(69.98±2.94) % vs (53.53±1.93)%, P=0.001]. The tumor weights of SK-Hep-1 group, sorafenib alone group, SK-Hep-1 si-YAP group and SK-Hep-1 si-YAP combined with sorafenib group were (0.96±0.08) g, (0.62±0.08) g, (0.70±0.06) g and (0.27±0.02) g, respectively. The tumor weights of sorafenib alone group and SK-Hep-1 si-YAP group were significantly lower than that of SK-Hep-1 group (P=0.012 and P=0.031, respectively). The tumor weight of SK-Hep-1 si-YAP combined with sorafenib group was significantly lower than that of SK-Hep-1 si-YAP group (P=0.001). Conclusions: The expression of YAP is upregulated in HCC cell lines, which regulates the proliferation, cell cycle, and sensitivity to sorafenib of HCC cells. YAP is a potential molecular target for HCC treatment.

[Comparison of therapeutics effects of transcatheter arterial chemoembolization combined with iodine-125 seed implantation and sorafenib for the treatment of hepatocellular carcinoma with portal vein tumor thrombosis].

Objective: To explore the factors affecting the prognosis of patients with hepatocellular carcinoma (HCC) combined with portal vein tumor thrombosis (PVTT), and to analyze the clinical value of transcatheter arterial chemoembolization (TACE) combined with iodine-125 seed implantation in such patients. Methods: A retrospective analysis of 53 patients with HCC combined with PVTT was performed. In the study group, 32 cases were treated with TACE combined with iodine-125 seed implantation, and 21 cases in the control group were treated with TACE combined with sorafenib. Survival analysis was carried out on eight factors such as gender, age, Child-Pugh classification, alpha fetoprotein level, portal vein tumor thrombosis (PVTT) type, forms of liver tumor, extra-hepatic metastasis and treatment modalities. The efficacy of TACE combined with iodine-125 seed implantation and TACE combined with sorafenib was further compared. The χ (2) test was used to evaluate the efficacy of the two groups. A single factor survival analysis was calculated by Kaplan-Meier estimator and multifactor survival analysis by Cox proportional hazards model. Results: All 53 patients were successfully treated. The median tumor progression time (mTTP) and median overall survival (mOS) were 8 months and 11 months, respectively. The disease control rate (DCR) of the study group for PVTT was 93.8%, which was significantly higher than that of the control group (61.9%, χ (2) = 6.448, P = 0.011). The difference was statistically significant; the objective remission rate of the study group for PVTT was 75.0%. Significantly higher than 9.5% in the control group, P < 0.05, the difference was statistically significant; the DCR of the primary tumor in the study group was 50.0%, which was lower than the 70.0% of the PVTT in the control group, P = 0.231, the difference was not statistically significant. The progression of primary HCC lesions in patients with multivariate survival analysis: Child-Pugh grade A patients were compared to grade B [Hazard ratio (HR) = 0.236, P = 0.003]; no extra-hepatic metastasis (HR = 0.258, P = 0.002); and TACE combined with iodine-125 seed implantation group compared with TACE combined sorafenib group (HR = 0.372, P = 0.002), the differences were statistically significant. Multivariate survival analysis of patients with overall survival: AFP < 400 ng/mL vs. AFP≥400 ng/mL (HR = 0.389, P = 0.030); Child-Pugh grade A vs. B (HR = 0.263, P = 0.006); and no extra-hepatic metastasis (HR = 0.306, P = 0.006), the differences were statistically significant. Conclusion: TACE combined with iodine-125 seed implantation for the treatment of HCC with PVTT can effectively control the progression of PVTT and intrahepatic lesions and improve the prognosis of patients.

[Research advances in the role of the Hippo-YAP/TAZ signaling pathway in primary liver cancer].

The Hippo-YAP/TAZ signaling pathway is an evolutionarily conserved pathway, which has been confirmed to play an important role in organ volume control, stem cell function, tissue regeneration, and tumorigenesis. Recent research findings show that the Hippo-YAP/TAZ signaling pathway is closely associated with the development and progression of primary liver cancer, and inhibition of the activity of this pathway may be a new method for the treatment of liver cancer. This article reviews the research advances in the role of the Hippo-YAP/TAZ signaling pathway in primary liver cancer.

Physiochemical properties of rice starch for production of vermicelli with premium quality.

Rice vermicelli is a main food consumed in China and Southeast Asia. Quality of rice vermicelli varies with rice cultivars. Parameters including amylose content, amylopectin distribution, thermal and pasting characteristics, gel texture and starch granules of three rice cultivars "Zhongjiazao 17", "Xiangzaoxian 24" and "Thai Jasmine Rice", were studied for their impacts on vermicelli quality. Results showed significant differences for the measurements of the quality traits and indicated that a favorable quality of vermicelli was not determined by any single factor instead of a combination of multi-parameters. A vermicelli with a favorable quality could be produced from a rice variety with a high apparent amylose content (>25%), a protein content of 11%, an intermediate gelatinization temperature and gel consistency, and a gel hardness (~3 N for a Rapid Viscosity Analyzer pasting) and moderate retrogradation capacity (a setback viscosity of 30-100 RVU).

Complex doping chemistry owing to Mn incorporation in nanocrystalline anatase TiO2 powders.

Mn-doped TiO2 powders with a wide range of nominal doping levels were fabricated using a one-step hydrothermal method followed by 400 °C annealing. Anatase powders with a uniform size distribution below 10 nm were obtained. The maximum solubility of Mn in the TiO2 lattice was around 30%, beyond which the Mn3O4 compound appeared as a secondary phase. The optical absorption edges for Mn-doped anatase TiO2 were red-shifted effectively through increasing Mn content. Alloying chemistry and associated elemental valences were elaborated through combining X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and theoretical simulation in the framework of density functional theory (DFT). The results showed that the Mn species exhibited mixed valence states of 3+ and 4+ in anatase TiO2, with the latter being the key to remarkable photocatalytic performance.

A replicating plasmid-based vector for GFP expression in Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae (M. hyopneumoniae) causes porcine enzootic pneumonia (PEP) that significantly affects the pig industry worldwide. Despite the availability of the whole genome sequence, studies on the pathogenesis of this organism have been limited due to the lack of a genetic manipulation system. Therefore, the aim of the current study was to generate a general GFP reporter vector based on a replicating plasmid. Here, we describe the feasibility of GFP reporter expression in M. hyopneumoniae (strain 168L) controlled by the p97 gene promoter of this mycoplasma. An expression plasmid (pMD18-TOgfp) containing the p97 gene promoter, and origin of replication (oriC) of M. hyopneumoniae, tetracycline resistant marker (tetM), and GFP was constructed and used to transform competent M. hyopneumoniae cells. We observed green fluorescence in M. hyopneumoniae transformants under fluorescence microscopy, which indicates that there was expression of the GFP reporter that was driven by the p97 gene promoter. Additionally, an electroporation method for M. hyopneumoniae with an efficiency of approximately 1 x 10(-6) transformants/µg plasmid DNA was optimized and is described herein. In conclusion, our data demonstrate the susceptibility of M. hyopneumoniae to genetic manipulation whereby foreign genes are expressed. This work may encourage the development of genetic tools to manipulate the genome of M. hyopneumoniae for functional genomic analyses.

An improved K-means clustering method for cDNA microarray image segmentation.

Microarray technology is a powerful tool for human genetic research and other biomedical applications. Numerous improvements to the standard K-means algorithm have been carried out to complete the image segmentation step. However, most of the previous studies classify the image into two clusters. In this paper, we propose a novel K-means algorithm, which first classifies the image into three clusters, and then one of the three clusters is divided as the background region and the other two clusters, as the foreground region. The proposed method was evaluated on six different data sets. The analyses of accuracy, efficiency, expression values, special gene spots, and noise images demonstrate the effectiveness of our method in improving the segmentation quality.

Apoptosis induced by lipid-associated membrane proteins from Mycoplasma hyopneumoniae in a porcine lung epithelial cell line with the involvement of caspase 3 and the MAPK pathway.

Lipid-associated membrane proteins (LAMPs) are important in the pathogenicity of the Mycoplasma genus of bacteria. We investigated whether Mycoplasma hyopneumoniae LAMPs have pathogenic potential by inducing apoptosis in a St. Jude porcine lung epithelial cell line (SJPL). LAMPs from a pathogenic strain of M. hyopneumoniae (strain 232) were used in the research. Our investigation made use of diamidino-phenylindole (DAPI) and acridine orange/ethidium bromide (AO/EB) staining, terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) analysis, and Annexin-V-propidium iodide staining. After LAMP treatment for 24 h, typical changes were induced, chromosomes were concentrated, apoptotic bodies were observed, the 3'-OH groups of cleaved genomes were exposed, and the percentage of apoptotic cells reached 36.5 ± 11.66%. Caspase 3 and caspase 8 were activated and cytochrome c (cyt c) was released from the mitochondria into the cytoplasm; poly ADP ribose polymerase (PARP) was digested into two fragments; p38 mitogen-activated protein kinase (MAPK) was phosphorylated; and the expression of pro-apoptosis protein Bax increased while the anti-apoptosis protein Bcl-2 decreased. LAMPs also stimulated SJPL cells to produce nitric oxide (NO) and superoxide. This study demonstrated that LAMPs from M. hyopneumoniae can induce apoptosis in SJPL cells through the activation of caspase 3, caspase 8, cyt c, Bax, and p38 MAPK, thereby contributing to our understanding of the pathogenesis of M. hyopneumoniae, which should improve the treatment of M. hyopneumoniae infections.

A rapid and sensitive loop-mediated isothermal amplification procedure (LAMP) for Mycoplasma hyopneumoniae detection based on the p36 gene.

The aim of this study was to establish a method for sensitive and rapid diagnosis of Mycoplasma hyopneumoniae in clinical specimens. To this effect, we employed three sets of primers specifically designed for amplification of nucleic acids under isothermal conditions. After optimization of reaction conditions, M. hyopneumoniae could be successfully detected at 63°C in 45 min through use of the loop-mediated isothermal amplification (LAMP) assay. A positive reaction was identified visually as white precipitate and confirmed by gel electrophoresis. The detection limit for this assay was 10 copies/µL, as observed by electrophoretic analysis. The accuracy of the LAMP reaction was confirmed by restriction endonuclease digestion as well as by direct sequencing of the amplified product. This method can specifically detect M. hyopneumoniae; other species with high homology and other bacterial and virus strains gave negative results. To test the utility of this procedure, the LAMP assay was applied to 40 clinical samples collected from swine lung tissues experimentally challenged with M. hyopneumoniae isolates, and compared to the results from a real-time polymerase chain reaction (PCR) assay. A concordance of 100% was observed between the two assays. In conclusion, the results from our study demonstrated that the LAMP assay provided a rapid reaction and was inexpensive to perform, with no need of complex instruments or systems such as Geneamp PCR. The LAMP assay may therefore be applied in routine diagnosis in the clinical laboratory and for in-field detection of M. hyopneumoniae infection.

Comparative analysis of mucosal immunity to Mycoplasma hyopneumoniae in Jiangquhai porcine lean strain and DLY piglets.

The Jiangquhai porcine lean strain (JQHPL) is a new pork meat-type strain that has been developed in recent years from the parent lines Duroc, Fengjing, and Jiangquhai pigs (DurocxFengjing pigxJiangquhai pig). Enzootic pneumonia (EP) in pigs induced by Mycoplasma hyopneumoniae (M. hyopneumoniae) is a chronic respiratory disease of pigs, generating high economic losses in the swine industry. Here, we investigated the degree of resistance to M. hyopneumoniae for the Jiangquhai porcine lean strain and the Duroc x Landrace x Yorkshire (DLY) pigs, which are Western commercial pigs that have been introduced in China. A total of 209 DLY piglets and 221 JQHPL piglets from 19 Landrace x Yorkshire and 22 JQHPL M. hyopneumoniae positive gestating sows with different expected dates of confinement were selected and raised in the same M. hyopneumoniae positive farrowing barn. When the oldest suckling piglets were 37 days old, nasal swabs were collected from all the piglets (ranging from 4 to 37 days old) to detect the M. hyopneumoniae pathogen using n-PCR and M. hyopneumoniae specific SIgA using ELISA. Positive M. hyopneumoniae infection rates in both the strains increased with age; however, positive rates for JQHPL were lower compared to DLY at 14 to 35 days old. The level of the specific SIgA rose rapidly in JQHPL respiratory tracts, particularly in piglets 21 to 35 days in age compared to DLY piglets of the same age; however, the level of the specific SIgA in DLY also marginally increased. In conclusion, JQHPL pigs exhibits higher resistance to M. hyopneumoniae compared to DLY. It is possible that this characteristic is caused by the faster and stronger mucosal immunity phenotype of the JQHPL strain.

[Progress in research of incidence of aortic dissection and risk factors].

The incidence rate of aortic dissection (AD) is low, but it is highly fatal in the acute phase. Miss diagnosis and misdiagnosis can occur occasionally, resulting the miss of the best intervention time. Research on the epidemiological characteristics and of AD and related risk factors can identify high-risk groups, make screening and diagnosis as soon as possible and effectively control the changeable risk factors to reduce the incidence of AD and improve the outcome of AD cases. This paper summarizes the progress in research of the epidemiological characteristics of AD and related risk factors in order to promote early prevention and diagnosis of AD, improve the AD case management and intervention level.

Combined effects of goserelin and tamoxifen on estradiol level, breast density, and endometrial thickness in premenopausal and perimenopausal women with early-stage hormone receptor-positive breast cancer: a randomised controlled clinical trial.

BACKGROUND: This study is to investigate the effects of geserelin+tamoxifen (TAM) on estradiol level, breast density (BD), endometrial thickness (ET), and blood lipids in premenopausal and perimenopausal women with hormone receptor-positive early-stage breast cancer. METHODS: This study recruited 110 premenopausal and perimenopausal patients with hormone receptor-positive early-stage breast cancer between 22 June 2008 and 31 December 2009 and randomly assigned them to receive either goserelin plus TAM or TAM alone for 1.5 years. Blood levels of sex hormones and lipids and ET were determined at 0, 3, 6, 12, and 18 months. Contralateral BD was also measured at 0, 12, and 18 months. RESULTS: Five participants dropped out of the goserelin plus TAM group, and two participants dropped out of the TAM-alone group before initiation of endocrine therapy. The rest of patients received scheduled treatment and 3 years of median follow-up. No serious adverse effects were observed, and only two local recurrences have been observed in these patients. Estradiol level and BD were lower in the goserelin plus TAM group than in the TAM-alone group (P<0.05). The endometrium in the goserelin plus TAM group was significantly thinner than that in the TAM-alone group (P<0.05), and women in the TAM-alone group exhibited endometrial thickening over the course of the study. Furthermore, no significant differences in blood lipid levels were reported between the two groups. CONCLUSION: The data from the current study demonstrated that the addition of goserelin to TAM results in downregulation of estradiol level, followed by significant reduction in BD and ET in premenopausal and perimenopausal women with hormone receptor-positive breast cancer, which may eventually lead to better outcome in these patients.

Novel ZnO nanorod films by chemical solution deposition for planar device applications.

Smooth and continuous ZnO films consisting of densely packed ZnO nanorods (NRs), which can be used for electronic device fabrication, were synthesized using a hydro-thermo-chemical solution deposition method. Such devices would have the novelty of high performance, benefiting from the inherited unique properties of the nanomaterials, and can be fabricated on these smooth films using a conventional, low cost planar process. Photoluminescence measurements showed that the NR films have much stronger shallow donor to valence band emissions than those from discrete ZnO NRs, and hence have the potential for the development of ZnO light emission diodes and lasers, etc. The NR films have been used to fabricate large area surface acoustic wave devices by conventional photolithography. These demonstrated two well-defined resonant peaks and their potential for large area device applications. The chemical solution deposition method is simple, reproducible, scalable and economic. These NR films are suitable for large scale production on cost-effective substrates and are promising for various fields such as sensing systems, renewable energy and optoelectronic applications.

Fine mapping and characterization of a novel dwarf and narrow-leaf mutant dnl1 in rice.

Plant height is one of the most important agronomic traits of rice (Oryza sativa). Dwarf mutants are ideal materials for research on the mechanisms of regulation of rice plant height. We examined a new dwarf and narrow-leaf mutant dnl1. Phenotypic analysis showed that the dnl1 mutant has a thinner culm and more tillers, but the number of grains per panicle, the seed setting rate and the grain weight of dnl1 mutant were found to be significantly lower than in the wild-type. Based on scanning electron microscopic observations, the number of cells in the y-axis in internodes was significantly lower than in the wild-type. In phytohormone induction experiments, dnl1 was gibberellic acid-insensitive. The expression of some genes involved in the gibberellins metabolic pathways was affected in the dnl1 mutant, based on the real-time PCR analysis, suggesting that the dnl1 gene likely plays a role in gibberellin metabolic pathways. Genetic analysis showed that the dwarf and narrow leaf phenotype is controlled by a novel single recessive gene, here referred to as the dwarf and narrow leaf 1 (dnl1), which is located within the region between markers Ind12-11 and RM8214 on the short arm of chromosome 12. By means of fine-mapping strategy, the dnl1 gene was localized within an interval of 285.75 kb physical distance. These results will be useful for dnl1 gene cloning and to improve our understanding of the molecular mechanisms involved in the regulation of growth and development of rice.

Investigation of the hydrogen bonding in ice Ih by first-principles density function methods.

It is a well recognized difficult task to simulate the vibrational dynamics of ices using the density functional theory (DFT), and there has thus been rather limited success in modelling the inelastic neutron scattering (INS) spectra for even the simplest structure of ice, ice Ih, particularly in the translational region below 400 cm(-1). The reason is partly due to the complex nature of hydrogen bonding (H-bond) among water-water molecules which require considerable improvement of the quantum mechanical simulation methods, and partly owing to the randomness of protons in ice structures which often requires simulation of large super-lattices. In this report, we present the first series of successful simulation results for ice Ih using DFT methods. On the basis of the recent advancement in the DFT programs, we have achieved for the first time theoretical outcomes that not only reproduce the rotational frequencies between 500 to 1200 cm(-1) for ice Ih, but also the two optic peaks at ∼240 and 320 cm(-1) in the translational region of the INS spectra [J. C. Li, J. Chem. Phys 105, 6733 (1996)]. Besides, we have also investigated the impact of pairwise configurations of H(2)O molecules on the H-bond and found that different proton arrangements of pairwise H(2)O in the ice Ih crystal lattice could not alter the nature of H-bond as significantly as suggested in an early paper [J. C. Li and D. K. Ross, Nature (London) 365, 327 (1993)], i.e., reproducing the two experimental optic peaks do not need to invoke the two H-bonds as proposed in the previous model which led to considerable debates. The results of this work suggest that the observed optic peaks may be attributed to the coupling between the two bands of H-O stretching modes in H(2)O. The current computational work is expected to shed new light on the nature of the H-bonds in water, and in addition to offer a new approach towards probing the interaction between water and biomaterials for which H-bond is essential.