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Litchi (Litchi chinensis) pepper spot disease results in black spotting symptoms on litchi fruits. This disease was first observed on litchi cultivar Guiwei, in Guangzhou, China, in 2009, and then found widespread in other litchi‐growing regions of China. Colletotrichum isolates were consistently recovered from typical black spot lesions of diseased fruits with frequency ranging from 83% to 100%. Three representative Colletotrichum isolates from Maoming, Guangzhou and Shenzhen were selected for identification and pathogenicity testing in the field. Based on morphology and phylogenetic analysis using the ribosomal internal transcribed spacer region (ITS), glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), calmodulin (CAL), actin (ACT), β‐tubulin (TUB2) and glutamine synthetase (GS) gene sequences, the three isolates were identified as C. siamense. In the pathogenicity experiments, typical symptoms appeared on the inoculated litchi fruits, including black spots and green patches around these black spots. These symptoms were consistent with the symptoms originally observed in the field. Colletotrichum siamense was successfully reisolated from the typical black spot lesions of the inoculated litchi fruits. To the authors' knowledge, this is the first report on characterization of C. siamense as the causal agent of litchi pepper spot disease in mainland China by successful inoculation on fruits under field conditions. [ABSTRACT FROM AUTHOR]

Large-diameter polishing pads play an important role in chemical mechanical polishing (CMP) and are vital to large-aperture plane optics. The surface profile of a wafer is closely related to the profile accuracy of the polyurethane pad. To attain a high-precision surface, the polishing pad is dressed using a diamond dresser. In the present study, a pad dressing model was proposed as a means of analysing how any geometry errors in the polishing machine affect the profile accuracy by observing the trajectory of the moving dresser tool. Based on the spherical surface generation method, the influence of any tilt and motion error on the profile accuracy of the pad was studied. To verify the accuracy of the model, a variety of analyses and dressing experiments were performed using PPS100 and KPJ1700 CMP machines. The results of these experiments showed that the proposed model could effectively predict the profile accuracy of the pad after the dressing process. However, because of uncertainty in the measurements, there was a degree of error between the predicted and measured values, although this was never > 5%. Moreover, the results demonstrated that the main geometry error was the dressing spindle's tilt angle which, if minimised, resulted in a higher dressing profile accuracy for the polyurethane pad. [ABSTRACT FROM AUTHOR]

Bee pollen is a health food with a wide range of nutritional and therapeutic properties. However, the bioactive compounds of bee pollen have not been extensively revealed due to low efficacy in separation. High-speed counter-current chromatography (HSCCC) and solvent extraction were applied to separate tyrosinase inhibitors from camellia pollen in this study. The camellia pollen extracts prepared with petroleum ether, ethyl acetate, and n-BuOH have tyrosinase inhibitory activity. Acidic hydrolysis could promote the tyrosinase inhibitory activity of crude sample. Three fractions with tyrosinase inhibitory activity were separated from the hydrolysate by a one-step HSCCC procedure. Among the fractions, two chemicals were sufficiently purified and identified to be levulinic acid (LA) and 5-hydroxymethylfurfural (5-HMF). The recovery was 0.80 g kg-1 pollen for LA and 1.75 g kg-1 pollen for 5-HMF; and their purity was all over 98%. The study demonstrates that HSCCC method is powerful for preparative separation of tyrosinase inhibitors from camellia pollen. [ABSTRACT FROM AUTHOR]

Bee pollen is a health food with a wide range of nutritional and therapeutic properties. However, the bioactive compounds of bee pollen have not been extensively revealed due to low efficacy in separation. High-speed counter-current chromatography (HSCCC) and solvent extraction were applied to separate tyrosinase inhibitors from camellia pollen in this study. The camellia pollen extracts prepared with petroleum ether, ethyl acetate, and n-BuOH have tyrosinase inhibitory activity. Acidic hydrolysis could promote the tyrosinase inhibitory activity of crude sample. Three fractions with tyrosinase inhibitory activity were separated from the hydrolysate by a one-step HSCCC procedure. Among the fractions, two chemicals were sufficiently purified and identified to be levulinic acid (LA) and 5-hydroxymethylfurfural (5-HMF). The recovery was 0.80 g kg-1 pollen for LA and 1.75 g kg-1 pollen for 5-HMF; and their purity was all over 98%. The study demonstrates that HSCCC method is powerful for preparative separation of tyrosinase inhibitors from camellia pollen. [ABSTRACT FROM AUTHOR]

Background Faecal microbiota transplantation ( FMT) has become routine in managing recurrent C. difficile infection ( CDI) refractory to antibiotics. Aim To compare clinical response and improvements in colonic microbiota diversity in subjects with recurrent CDI using different donor product. Methods Seventy-two subjects with ≥3 bouts of CDI were randomised in a double-blind study to receive fresh, frozen or lyophilised FMT product via colonoscopy from 50 g of stool per treatment from eight healthy donors. Recipients provided stools pre- and 7, 14 and 30 days post- FMT for C. difficile toxin and, in a subset, microbiome composition by 16S rRNA gene profiling. Results Overall resolution of CDI was 87% during 2 months of follow-up after FMT. Stool samples before FMT had significantly decreased bacterial diversity with a high proportion of Proteobacteria compared to donors. Cure rates were highest for the group receiving fresh product seen in 25/25 (100%), lowest for the lyophilised product 16/23 (78%; P = 0.022 vs. fresh and 0.255 vs. frozen) and intermediate for frozen product 20/24 ( P = 0.233 vs. fresh). Microbial diversity was reconstituted by day 7 in the subjects receiving fresh or frozen product. Improvement in diversity was seen by day 7 in those randomised to lyophilised material with reconstitution by 30 days. Conclusions Comparative efficacy in faecal microbiota transplantation was observed in subjects receiving fresh or frozen faecal product from the same donors. The lyophilised product had a slightly lowered efficacy compared with fresh product, but it resembled other treatments in microbial restoration 1 month after faecal microbiota transplantation. [ABSTRACT FROM AUTHOR]

Distinguishing label-free malignant cells from healthy ones by their laser scattering spectra is still a tough challenge in label-free cells detection methods. During cells malignant transferring, some tiny structural differences occurs. The nucleus, as the most important internal structure, has very close relationships with cell's healthy state. In this paper, cells with similar size but different tiny nucleus differences are set as the research objects. A novel cell's laser scattering processing algorithm, even interval incident angle (EIIA) algorithm, is developed which is effective in distinguish label-free cells with tiny nucleus' size difference. The laser scattering spectra of human acute leukaemia Jurkat cell models with different nuclei are processed by EIIA to test its sensitivity and reliability. The results prove that cell's original tightly compacted laser scattering spectra have been well separated by EIIA. A consistent rule for cell's nucleus becoming larger can be obviously observed in EIIA processed laser scattering results, which is promising to be an effective standard for identifying malignant larger nucleus cells from healthy ones; therefore, a valid pathway for identify label-free cells simply and directly by their laser scattering spectra can be implemented by EIIA. Also, it may supply an important clinic diagnosis tool to detect malignant cells in early cancerous stage without any dying and marking procedures. [ABSTRACT FROM AUTHOR]

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Background. Traveler's diarrhea is the most common medical complaint of international visitors to developing regions. Previous findings suggested that noroviruses (NoVs) are an underappreciated cause of traveler's diarrhea. Methods. In the present study, we sought to define the presence of NoVs in 320 acute diarrheic stool samples collected from 299 US students who traveled to Guadalajara, Cuernavaca, or Puerto Vallarta, Mexico, during the period from 2007 through 2008. Conventional and quantitative real-time polymerase chain reaction assays were used to detect and determine NoV loads in stool samples. NoV strains were characterized by purification of viral RNA followed by sequencing of the viral capsid protein 1 gene. Sequences were compared using multiple sequence alignment, and phylogenetic trees were generated to evaluate the evolutionary relatedness of the viral strains associated with cases of traveler's diarrhea. Results. NoV RNA was detected in 30 (9.4%) of 320 samples. Twelve strains belonged to genogroup I, and 18 strains belonged to genogroup II. NoV prevalence was higher in the winter season than in the summer season (23% vs 7%, respectively; P=.001 ). The cDNA viral loads of genogroup I viruses were found to be 500-fold higher than those of genogroup II strains. Phylogenetic analysis revealed a diverse population of No strains over different locations and years. Conclusions. NoV strains are important causes of traveler's diarrhea in Mexico, especially during the wintertime, and US students in Mexico may represent a suitable group for future NoV vaccine efficacy trials. [ABSTRACT FROM AUTHOR]

Aim This was an in vitro study to analyse the susceptibility of Clostridium difficile isolates to rifampin and rifaximin. Methods Stool samples from patients who had nosocomial diarrhoea and C difficile toxin B at a university hospital between August 2006 and December 2007 were cultured for C difficile. Susceptibility of C difficile isolates to rifaximin and rifampin was determined by agar dilution and E strips, respectively. C difficile isolates were analysed via PCR for genes encoding toxins A and B, for binary toxin (BT), and for partial deletions of the tcdC gene (tcdC-del). Results Rifaximin exhibited high-level activity against 359 C difficile isolates, with MIC50 <0.01 µg/ml and MIC90 0.25 µg/ml; rifampin had MIC50 <0.002 µg/ml and MIC90 4 µg/ml. Among isolates analysed, 55 (15%) were positive for BT and tcdC-del. 28 (8% of 359) isolates were resistant to rifampin (≥32 µg/ml), of which 6 (2% of 359) were resistant to rifaximin and rifampin with MIC values ≥32 µg/ml. 2 of the 28 isolates resistant to rifampin were A+/B+/BT+/tcdC-del+, 5 were A+/B+/BT-/tcdC-del+, 4 were A+/B+/BT+/tcdC-del-, 13 were A+/B+/BT-/tcdC-del-, and 4 had no detectable toxin genes. Of the 11 isolates resistant to rifaximin alone, 1 was A+/B+/BT-/tcdC-del+, 2 were A+/B+/BT+/tcdC-del-, 6 were A+/B+/BT-/tcdC-del-, and 2 had no detectable toxin genes. Conclusions The study demonstrates that rifaximin has high-level activity against C difficile in vitro. Determination of resistance to rifampin by E strip did not predict rifaximin resistance. [ABSTRACT FROM AUTHOR]

Background: Simple methods for detecting secretory immunoglobulin A (sIgA) immune responses following natural enteric infection and oral immunization are needed.Methods: Fourteen students from the United States acquiring enterotoxigenic Escherichia coli (ETEC) diarrhea in Mexico were studied for fecal immunoglobulin A (IgA) response to their homologous infecting ETEC and to heat-labile (LT) toxin of ETEC using Dot-Blot microfiltration and enzyme-linked immunosorbent assay (ELISA) methods. Paired stool samples were collected on the day of presentation and 5 days later.Results: Twelve of 14 (86%) patients with ETEC diarrhea (5 heat-stable [ST]/LT positive, 4 LT-only, and 5 ST-only) developed sIgA antibodies directed against their homologous ETEC and 6 (66%) of the 9 patients harboring ST/LT or LT-only strains developed sIgA LT-antibody responses. Single fecal samples from 9 healthy controls were negative for ETEC specific antibodies.Conclusions: Patients with diarrhea due to noninvasive ST/LT ETEC and LT ETEC commonly produce a specific sIgA antibody response early in the illness. We feel that the methods employed will be useful to detect antibodies during natural infection by enteric pathogens and following oral enteric vaccine administration. [ABSTRACT FROM AUTHOR]

Studies several students in the U.S. for fecal immunoglobulin A response to their homologous infecting enterotoxigenic Escherichia coli (ETEC) and to heat-labile (LT) toxin of ETEC. Information on ETEC; Methods used; Frequency of local antibody responses to homologous ETEC bacteria and to LT toxin in several travelers with ETEC diarrhea.

Unlabelled: This study examined whether high presentation rates of clicks while recording brainstem auditory evoked responses (BAER) can improve the detection of central auditory impairment in asphyxiated neonates using the BAER. The BAER was analysed at different presentation rates of clicks within the first week after birth in 38 term neonates who suffered perinatal asphyxia. At the routinely used 21 s(-1) clicks all BAER wave latencies increased significantly (ANOVA, p < 0.05-0.01). After excluding five neonates who had a significantly elevated BAER threshold, only wave V latency increased slightly (p < 0.05). The interpeak intervals of I-V and III-V also increased slightly (both p < 0.05). Similar results were found at 51 s(-1) clicks. As the clicks were increased to 91 s(-1), the III-V interval increased more significantly (p < 0.01) and the III-V/I-III interval ratio also increased significantly (p < 0.01). In particular, wave V amplitude reduced more significantly than that in normal term controls (p < 0.01). Compared with values in the controls, wave V amplitude reduced by 4.5%, 12.2% and 24.7% at 21, 51 and 91 s(-1) clicks, respectively.Conclusion: Although a moderate increase in the rate (e.g. 51 s(-1)) while recording the BAER did not improve the detection of hypoxic-ischaemic auditory impairment, a significant increase (e.g. 91 s(-1)) did, which mainly indicates an abnormal reduction in wave V amplitude. [ABSTRACT FROM AUTHOR]

Unlabelled: Seventy preterm babies who were born with a birthweight <1500 g were studied with brainstem auditory evoked responses (BAER) at 37-42 wk of postconceptional age. The data were compared with those of normal term neonates to determine the prevalence of hearing impairment in preterm very low birthweight (VLBW) babies when they reached term. The BAER was recorded with click stimuli at 21 s(-1). Wave I and V latencies increased significantly (ANOVA p < 0.01 and 0.001). I-V and III-V intervals also increased significantly (p < 0.05 and 0.001). Wave V amplitude and V/I amplitude ratio did not differ significantly from those in the normal term controls. Ten of the 70 VLBW babies had a significant elevation in BAER threshold (>30 dB normal hearing level). Eleven had an increase in I-V interval (>2.5 SD above the mean in the normal controls) and one had a decrease in V/I amplitude ratio (<0.45). These results suggest that 14% (10/70) of the VLBW babies had a peripheral hearing impairment and 17% (12/70) a central impairment. Three babies had both an increase in I-V interval and an elevation in BAER threshold, suggesting that 4% (3/70) had both peripheral and central impairments. Thus, the total prevalence of hearing impairment was 27% (19/70).Conclusion: About one in four preterm VLBW babies has peripheral and/or central hearing impairment at term. VLBW and its associated unfavourable perinatal factors predispose the babies to hearing impairment. [ABSTRACT FROM AUTHOR]

Background/Aims: Bacterial enteropathogens, the major cause of travelers’ diarrhea, are customarily treated with antibacterial drugs. Rifaximin, a nonabsorbed antimicrobial was examined as treatment for travelers’ diarrhea. Methods: A randomized, prospective, double-blind clinical trial was carried out in 72 US adults in Mexico. Patients with acute diarrhea received one of three doses of rifaximin (200, 400 and 600 mg t.i.d.) or trimethoprim/sulfamethoxazole (TMP/SMX, 160 mg/800 mg b.i.d.) for 5 days. Results were compared with data from 2 placebo-treated historical control populations. Results: The shortest duration of treated diarrhea was seen in the group receiving 200 mg rifaximin t.i.d (NS). Clinical failure to respond to treatment occurred in 6 of 55 (11%) rifaximin-treated subjects versus 5 of 17 (29%) of TMP/SMX-treated subjects (NS). Sixteen of twenty (80%) of the enteropathogens isolated from the rifaximin-treated subjects and 7 of 7 (100%) from the TMP/SMX group were eradicated by treatment (NS). Sixteen of twenty-four (67%) enteropathogens identified were susceptible to TMP and all 24 were inhibited by ≤50 µg/ml of rifaximin. Rifaximin reduced the number of unformed stools passed during the first 24 h of treatment when compared with 2 control placebo groups (3.3 versus 5.1; p = 0.008 and 0.0001) and led to a reduced duration of post-enrollment diarrhea (mean values of 43.1 versus 68.1 and 81.9 h; p = 0.001). Conclusions: Rifaximin shortened the duration of travelers’ diarrhea compared with TMP/SMX and 2 earlier studied placebo-treated groups. A poorly absorbed drug if effective in treating bacterial diarrhea has pharmacologic and safety advantages over the existing drugs. [ABSTRACT FROM AUTHOR]

A highly compact (25 × 25 × 0.8 mm³) dual-band folded square-loop antenna is proposed for reading near-field RF identification (RFID) tags. The antenna has a strong and uniform magnetic field in the nearfield zone of the square loop. The side length of the square loop (~λ/16) generates resonant frequencies in two conventional modes (0.5λ and 1.0λ). Experimental interrogation of a small RFID button tag attached to a blood sample collection tube showed that the antenna has a small interrogation zone (15 × 15 mm²), which avoids unnecessary interrogation. Experiments also showed that with an input power of 25 dBm, the antenna can tag at a distance of up to 40 mm, which confirmed its suitability for reading button-type RFID tags attached to blood sample collection tubes and other specimen containers. [ABSTRACT FROM AUTHOR]

This study sought to determine whether a specific polymerase chain reaction (PCR) for enterotoxigenic Escherichia coli (ETEC) toxins after chaotropic extraction of DNA from stool would increase the detection of ETEC over that of conventional oligonucleotide probe hybridization of 5 E. coli colonies per stool sample (a standard method). By DNA hybridization, 29 (21%) of 140 patients were positive for ETEC, and 59 (42%) of 140 were positive for ETEC when PCR was used. Sensitivity of the PCR assay was confirmed through spiked stool experiments to be approximately 100-1000 ETEC colonies per sample. Specificity of the assay was determined by showing an absence of ETEC by the PCR technique in a subgroup of 48 subjects and by confirming the presence of ETEC DNA of positive samples by dot blot procedure. PCR technique detected significantly more ETEC infections in these subjects than did the hybridization method (P<.0001). [ABSTRACT FROM AUTHOR]

Based on silicon on insulator (SOI) technology, a novel high temperature pressure sensor with high frequency response is designed and fabricated, in which a buried silicon dioxide layer in the silicon material is developed by the separation by implantation of oxygen (SIMOX) technology. This layer can isolate leak currents between the top silicon layer for the detecting circuit and body silicon at a temperature of about 200 °C. In addition, the technology of silicon and glass bonding is used to create a package of the sensor without internal strain. A structural model and test data from the sensor are presented. The experimental results showed that this kind of sensor possesses good static performance in a high temperature environment and high frequency dynamic characteristics, which may satisfy the pressure measurement demands of the oil industry, aviation and space, and so on. [ABSTRACT FROM AUTHOR]

The article discusses the use of a new antibiotic safely for preventing travelers' diarrhea. Daily antibiotics can prevent travelers' diarrhea but have many adverse effects, such as making bacteria in the body more resistant to antibiotics. Therefore, the risk of taking daily antibiotics to prevent travelers' diarrhea is usually considered greater than the benefit. Rifaximin, an antibiotic used in other countries to treat diarrhea, recently became available in the U.S. Rifaximin is an effective treatment for travelers' diarrhea once it has developed and might also be useful for preventing travelers' diarrhea.