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1.
Han  Lei  Zhao  Xiang  Huang  Tianye  Ding  Huafeng  Wu  Chuan 《Plasmonics (Norwell, Mass.)》2019,14(6):1743-1750
Plasmonics - Surface plasmon resonance (SPR) biosensor is widely used for its high precision and real-time analysis. In this paper, SPR biosensor based on the hybrid structure of metal–indium...  相似文献   

2.
Cell-penetrating peptide (CPP) based transfection systems (PBTS) are a promising class of drug delivery vectors. CPPs are short mainly cationic peptides capable of delivering cell non-permeant cargo to the interior of the cell. Some CPPs have the ability to form non-covalent complexes with oligonucleotides for gene therapy applications. In this study, we use quantitative structure–activity relationships (QSAR) , a statistical method based on regression data analysis. Here, an fragment QSAR (FQSAR) model is developed to predict new peptides based on standard alpha helical conformers and Assisted Model Building with Energy Refinement molecular mechanics simulations of previous peptides. These new peptides were examined for plasmid transfection efficiency and compared with their predicted biological activity. The best predicted peptides were capable of achieving plasmid transfection with significant improvement compared to the previous generation of peptides. Our results demonstrate that FQSAR model refinement is an efficient method for optimizing PBTS for improved biological activity.  相似文献   

3.
Instead of vision, many nocturnal animals use alternative senses for navigation and object detection in their dark environment. For this purpose, weakly electric mormyrid fish employ active electrolocation, during which they discharge a specialized electric organ in their tail which discharges electrical pulses. Each discharge builds up an electrical field around the fish, which is sensed by cutaneous electroreceptor organs that are distributed over most of the body surface of the fish. Nearby objects distort this electrical field and cause a local alteration in current flow in those electroreceptors that are closest to the object. By constantly monitoring responses of its electroreceptor organs, a fish can detect, localize, and identify environmental objects.Inspired by the remarkable capabilities of weakly electric fish in detecting and recognizing objects, we designed technical sensor systems that can solve similar problems of remote object sensing. We applied the principles of active electrolocation to technical systems by building devices that produce electrical current pulses in a conducting medium (water or ionized gases) and simultaneously sense local current density. Depending on the specific task a sensor was designed for devices could (i) detect an object, (ii) localize it in space, (iii) determine its distance, and (iv) measure properties such as material properties, thickness, or material faults. Our systems proved to be relatively insensitive to environmental disturbances such as heat, pressure, or turbidity. They have a wide range of applications including material identification, quality control, non-contact distance measurements, medical applications and many more. Despite their astonishing capacities, our sensors still lag far behind what electric fish are able to achieve during active electrolocation. The understanding of the neural principles governing electric fish sensory physiology and the corresponding optimization of our sensors to solve certain technical tasks therefore remain ongoing goals of our research.  相似文献   

4.
The portfolio of impacts that are quantified in life cycle assessment (LCA) has grown to include rather different stressors than those that were the focus of early LCAs. Some of the newest life cycle impact assessment (LCIA) models are still in an early phase of development and have not yet been included in any LCA study. This is the case for sound emissions and noise impacts, which have been only recently modeled. Sound emissions are matter‐less, time dependent, and bound to the physical properties of waves. The way sound emissions and the relative noise impacts are modeled in LCA can show how new or existing matter‐less impacts can be addressed. In this study, we analyze, through the example of sound emissions, the specific features of a matter‐less impact that does not stem from the use of a kilogram of matter, nor is related to the emission of a kilogram of matter. We take as a case study the production of energy by means of wind turbines, contradicting the commonly held assumption that windmills have no emissions during use. We show how to account for sound emissions in the life cycle inventory phase of the life cycle of a wind turbine and then calculate the relative impacts using a noise LCIA model.  相似文献   

5.
In type 2 diabetes (T2D) prevention research, evidence for maintenance of risk factor reduction after three years of follow-up is needed. The objective of this study was to evaluate the long-term effectiveness of a combined lifestyle intervention aiming at controlling body weight (BW) and waist circumference (WC) in non-diabetic, overweight/obese adults living in a low socio-economic community. On Reunion Island, 445 adults living in deprived areas, aged 18–40 and at high-risk for T2D, were included in an intervention versus control trial for primary prevention (2001–2002). The intervention promoted a healthy diet and moderate regular physical activity, through actions strengthening individuals or community and improving living conditions. The control group received a one-shot medical information and nutritional advices. After the end of the trial (2003), 259 of the subjects participated in a follow-up study (2010–2011). The outcomes were the nine-year changes from baseline in BW, body mass index (BMI) and WC measurements, separately. Statistical analyses were performed on an intention-to-treat basis, using available and imputed datasets. At inclusion, T2D risk factors were prevalent: family history of diabetes in first-degree relatives (42%), women with a personal history of gestational diabetes (11%), total obesity (43%, median BMI 29.1 kg/m²) and central obesity (71%). At follow-up, the adjusted effect on imputed dataset was significant for WC -2.4 cm (95% confidence interval: -4.7 to -0.0 cm, p = 0.046), non-significant for BW -2.2 kg (-4.6 to +0.2 kg, p = 0.073) and BMI -0.81 kg/m² (-1.69 to +0.08 kg/m², p = 0.074). A specific long-term effect was the increased likelihood of reduction in adiposity: BW loss, BMI reduction, and WC reduction were more frequent in the intervention group. In the context of low socio-economic communities, our data support the assumption of long-term effect of lifestyle interventions targeting total obesity and central obesity two major drivers of T2D.  相似文献   

6.
The relationship of claw lesions to housing was studied in 36 sow herds. Eighteen herds with loose housing of pregnant sows and 18 herds with confined (stalled or tethered) pregnant sows, were followed over a 12 month period. Fifteen of the loose housing herds had partly slatted concrete floors, while 3 herds had other types of flooring. The mean herd prevalence proportion of sows with major claw lesions in loose housing herds with partly slatted floors was about twice as high as in the herds with confined sows. In the only loose housing herd with deep litter based on straw, the prevalence proportion of sows with major claw lesions was lower than any of the other loose or confined herds. Within herds with loose sows on partly slatted floors, the prevalence proportion of sows with major claw lesions seemed to be higher in the loose housing compartment than in the farrowing compartment. The prevalence proportion of sows with major claw lesions did not differ between loose herds with plastic slats and loose herds with concrete slats. kw|Keywords|k]pig; k]feet injuries; k]slatted floors; k]deep litter; k]epidemiology  相似文献   

7.
Concentration addition (CA) and independent action (IA) models are often applied to estimate the mixture toxicity of similarly and dissimilarly acting chemicals, respectively. An integrated addition model (IAM), called the “integrated CA with IA based on a multiple linear regression (ICIM) model” was recently proposed for predicting additive toxicity of non-interactive mixtures regardless of whether mixture components produce similar, dissimilar, or both similar and dissimilar modes of action. In the ICIM, the effective concentrations of mixtures experimentally tested were regarded as the response variable, and the results estimated by CA and IA were considered as the predictor variable. However, it can be highlighted that the multicollinearity problem (i.e., a linear relationship between predictor variables), which may be caused in the existing ICIM model employing ordinary least squares regression. Therefore, the objectives of this study were to develop and evaluate a Partial Least Squares-based IAM (PLS-IAM) not only to overcome the multicollinearity problem, but also to combine the CA and IA into an IAM using the latent variable that accounts for most of the variation in the response. Through four test datasets, this study showed that the PLS-IAM overall outperformed the other reference models, including the CA, IA, and ICIM models.  相似文献   

8.
A gp63PCR method was evaluated for the detection and characterization of Leishmania (Leishmania) (L.) parasites in canine lymph node aspirates. This tool was tested and compared to other PCRs based on the amplification of 18S ribosomal genes, a L. infantum specific repetitive sequence and kinetoplastic DNA minicircles, and to classical parasitological (smear examination and/or culture) or serological (IFAT) techniques on a sample of 40 dogs, originating from different L. infantum endemic regions in Tunisia. Sensitivity and specificity of all the PCR assays were evaluated on parasitologically confirmed dogs within this sample (N = 18) and control dogs (N = 45) originating from non–endemic countries in northern Europe and Australia. The gp63 PCR had 83.5% sensitivity and 100% specificity, a performance comparable to the kinetoplast PCR assay and better than the other assays. These assays had comparable results when the gels were southern transferred and hybridized with a radioactive probe. As different infection rates were found according to the technique, concordance of the results was estimated by (κ) test. Best concordance values were between the gp63PCR and parasitological methods (74.6%, 95% confidence intervals CI: 58.8–95.4%) or serology IFAT technique (47.4%, 95% CI: 23.5–71.3%). However, taken together Gp63 and Rib assays covered most of the samples found positive making of them a good alternative for determination of infection rates. Potential of the gp63PCR-RFLP assay for analysis of parasite genetic diversity within samples was also evaluated using 5 restriction enzymes. RFLP analysis confirmed assignment of the parasites infecting the dogs to L. infantum species and illustrated occurrence of multiple variants in the different endemic foci. Gp63 PCR assay thus constitutes a useful tool in molecular diagnosis of L. infantum infections in dogs in Tunisia.  相似文献   

9.
Dengue is a potentially fatal acute febrile illness caused by four mosquito-transmitted dengue viruses (DENV-1–4). Although dengue outbreaks regularly occur in many regions of the Pacific, little is known about dengue in the Republic of the Marshall Islands (RMI). To better understand dengue in RMI, we investigated an explosive outbreak that began in October 2011. Suspected cases were reported to the Ministry of Health, serum specimens were tested with a dengue rapid diagnostic test (RDT), and confirmatory testing was performed using RT-PCR and IgM ELISA. Laboratory-positive cases were defined by detection of DENV nonstructural protein 1 by RDT, DENV nucleic acid by RT-PCR, or anti-DENV IgM antibody by RDT or ELISA. Secondary infection was defined by detection of anti-DENV IgG antibody by ELISA in a laboratory-positive acute specimen. During the four months of the outbreak, 1,603 suspected dengue cases (3% of the RMI population) were reported. Of 867 (54%) laboratory-positive cases, 209 (24%) had dengue with warning signs, six (0.7%) had severe dengue, and none died. Dengue incidence was highest in residents of Majuro and individuals aged 10–29 years, and ∼95% of dengue cases were experiencing secondary infection. Only DENV-4 was detected by RT-PCR, which phylogenetic analysis demonstrated was most closely related to a virus previously identified in Southeast Asia. Cases of vertical DENV transmission, and DENV/Salmonella Typhi and DENV/Mycobacterium leprae co-infection were identified. Entomological surveys implicated water storage containers and discarded tires as the most important development sites for Aedes aegypti and Ae. albopictus, respectively. Although this is the first documented dengue outbreak in RMI, the age groups of cases and high prevalence of secondary infection demonstrate prior DENV circulation. Dengue surveillance should continue to be strengthened in RMI and throughout the Pacific to identify and rapidly respond to future outbreaks.  相似文献   

10.
Plasmonics - We present one of the simplest nanoscale systems for a high-performance refractive index (RI) sensor. We investigate analytically and numerically the transmission response of the...  相似文献   

11.

Background

Chikungunya virus (CHIKV) is a recently re-emerged arthropod borne virus responsible for a massive outbreak in the Indian Ocean and India, and extended to Southeast Asia as well as Italy. CHIKV has adapted to Aedes albopictus, an anthropophilic mosquito species widely distributed in Asia, Europe, Africa and America. Our objective was to determine the clinical and biological features of patients at the acute phase of CHIKV infection.

Methods and Findings

A prospective study enrolled 274 consecutive patients with febrile arthralgia recorded at the Emergency Department of the Groupe Hospitalier Sud-Réunion between March and May 2006. Three groups were defined: one group of 180 viremic patients (positive CHIKV RT-PCR), one group of 34 patients with acute post-viremic infection (negative CHIKV RT-PCR, positive anti-CHIKV IgM and negative IgG), and one group of 46 uninfected patients (negative CHIKV RT-PCR, anti-CHIKV IgM and IgG). Bivariate analyses of clinical and biological features between groups were performed. Patients with CHIKV viremia presented typically with asymmetrical bilateral polyarthralgia (96.5%) affecting the lower (98%) and small joints (74.8%), as well as asthenia (88.6%), headache (70%), digestive trouble (63.3%), myalgia (59%), exanthems (47.8%), conjunctival hyperhemia (23%) and adenopathy (8.9%). Vertigo, cutaneous dysesthesia, pharyngitis and haemorrhages were seldom observed. So far unreported symptoms such as chondrocostal arthralgia (20%), entesopathies (1.6%), talalgia (14%) were also noted. Prurit was less frequent during the viremic than post-viremic phase (13.9% vs. 41.2%; p<0.001), whereas lymphopenia was more frequent (87.6% vs. 39.4%; p<0.001). Others biological abnormalities included leukopenia (38.3%), thrombocytopenia (37.3%), increased ASAT and ALAT blood levels (31.6 and 7.3%, respectively) and hypocalcemia (38.7%). Lymphopenia <1,000/mm3 was very closely associated with viremic patients (Yule coefficient 0.82, positive predictive value 92.3%). Age under 65 was associated with a benign course, as no patients younger than 65 had to be hospitalized (Yule coefficient 0.78).

Conclusions

The diagnosis of CHIKV infection in acute phase is based on commonly accepted clinical criteria (fever and arthralgia), however clinical and biological diffrences exist in acute phase depending on whether or not the patient is within the viremic phase of the infection.  相似文献   

12.
Crosstalk between neurons and glia may constitute a significant part of information processing in the brain. We present a novel method of statistically identifying interactions in a neuron–glia network. We attempted to identify neuron–glia interactions from neuronal and glial activities via maximum-a-posteriori (MAP)-based parameter estimation by developing a generalized linear model (GLM) of a neuron–glia network. The interactions in our interest included functional connectivity and response functions. We evaluated the cross-validated likelihood of GLMs that resulted from the addition or removal of connections to confirm the existence of specific neuron-to-glia or glia-to-neuron connections. We only accepted addition or removal when the modification improved the cross-validated likelihood. We applied the method to a high-throughput, multicellular in vitro Ca2+ imaging dataset obtained from the CA3 region of a rat hippocampus, and then evaluated the reliability of connectivity estimates using a statistical test based on a surrogate method. Our findings based on the estimated connectivity were in good agreement with currently available physiological knowledge, suggesting our method can elucidate undiscovered functions of neuron–glia systems.  相似文献   

13.
The Tamm–Horsfall glycoprotein prepared by salt precipitation from urine was found to comprise a heterogeneous collection of aggregates. These could be disaggregated with 8m-urea, following which chromatography on a column of Bio-Gel A.15m yielded a homogeneous glycoprotein of mol.wt. 73000 together with several unidentified impurities. Gel filtration of normal plasma showed the glycoprotein to exist predominantly in a form that is eluted identically with the purified preparation. In one case, material of higher molecular weight was also detected. The purified glycoprotein was used to develop a rapid specific radioimmunoassay for its measurement in human serum or plasma by the use of the Tamm–Horsfall glycoprotein, labelled with 125I by the chloramine-t method as the tracer, an antiserum raised in rabbits, and separation of the bound and free fractions by a second antibody covalently linked to magnetizable particles. Parallelism was demonstrated between the standard preparation and samples. Recovery of added standard to serum varied between 99 and 109%. Total assay time was less than 4h with an intra-assay and inter-assay coefficient of variation of less than 10%. There were no significant differences in the ranges covered with regard to either age or sex, and no circadian rhythm was observed in normal subjects. A physiological range of 70–540ng/ml was established based on serum samples from 95 subjects with normal renal function, as defined by their serum creatinine and urea concentrations. No Tamm–Horsfall glycoprotein was detected in the serum of six anephric patients.  相似文献   

14.

Objectives

In the present study, we aimed to determine the effect of both active and passive smoking on the prevalence of the hearing impairment and the hearing thresholds in different age groups through the analysis of data collected from the Korea National Health and Nutrition Examination Survey (KNHANES).

Study Design

Cross-sectional epidemiological study.

Methods

The KNHANES is an ongoing population study that started in 1998. We included a total of 12,935 participants aged ≥19 years in the KNHANES, from 2010 to 2012, in the present study. Pure-tone audiometric (PTA) testing was conducted and the frequencies tested were 0.5, 1, 2, 3, 4, and 6 kHz. Smoking status was categorized into three groups; current smoking group, passive smoking group and non-smoking group.

Results

In the current smoking group, the prevalence of speech-frequency bilateral hearing impairment was increased in ages of 40−69, and the rate of high frequency bilateral hearing impairment was elevated in ages of 30−79. When we investigated the impact of smoking on hearing thresholds, we found that the current smoking group had significantly increased hearing thresholds compared to the passive smoking group and non-smoking groups, across all ages in both speech-relevant and high frequencies. The passive smoking group did not have an elevated prevalence of either speech-frequency bilateral hearing impairment or high frequency bilateral hearing impairment, except in ages of 40s. However, the passive smoking group had higher hearing thresholds than the non-smoking group in the 30s and 40s age groups.

Conclusion

Current smoking was associated with hearing impairment in both speech-relevant frequency and high frequency across all ages. However, except in the ages of 40s, passive smoking was not related to hearing impairment in either speech-relevant or high frequencies.  相似文献   

15.
Preeclampsia remains a leading cause of maternal and perinatal mortality and morbidity worldwide; however, its specific etiology still remains obscure. Some studies implicate poor maternal selenium status predisposing the mother to preeclampsia. This study was designed to determine changes in plasma selenium levels in women having preeclampsia as compared with those with normal pregnancy. In a nested case–control study, 650 normal primigravida in their first 24–28 weeks participated in the study. After 3 months of follow-up of all subjects, blood selenium levels were measured in 38 women presenting consecutively with preeclampsia and in 38 women having a normal pregnancy by atomic absorption spectrophotometry. Birth outcomes were recorded, such as gestational age at delivery, height, weight, birth head circumflex and 1-min Apgar score. Preeclampsia affects about 5.84 % of pregnancies, and in our study, there were no significant differences in age, anthropometric indices, and family history of preeclampsia between the preeclamptic and control groups. The selenium concentrations in plasma in women with preeclampsia were significantly lower as compared with those in women with normal pregnancy (70.63?±?21.41 versus 82.03?±?15.54 μg/L, p?<?0.05). Being in the bottom tertile of selenium concentration (less than 62.2 μg/L) was associated with greater risk of preeclampsia in pregnant women. The reduced selenium in the maternal circulations observed in the preeclamptic mothers support the hypothesis that insufficient selenium concentration may be a contributing factor to the pathophysiological mechanisms associated with preeclampsia, and optimizing the dietary selenium intake through supplementation could produce demonstrable clinical benefits.  相似文献   

16.
Mikhailov  M. I.  Nührenberg  J.  Zille  R. 《Plasma Physics Reports》2019,45(12):1171-1176
Plasma Physics Reports - The compatibility of global MHD modes stability and good collisionless confinement of fast particles is studied in a quasi-axisymmetric tokamak–stellarator hybrid. It...  相似文献   

17.
18.
This pilot study tested the efficacy of an audio–visual stimulation (AVS) program for the promotion of sleep in individuals with chronic pain. Insomnia and chronic pain are common comorbid conditions and their relationship has been viewed as bidirectional. Recent studies suggest a relatively dominant role of sleep in this dyad. The premise of this pilot study was that AVS enhances low frequency while reducing high frequency brain activity resulting in decreased hyperarousal and improved sleep with potential consequent reduction in pain. We conducted a pilot intervention study of AVS using a pre–post design. Participants self-administered a 30-min AVS program nightly at bedtime for 1 month. Sleep and pain were assessed at baseline and at the conclusion of the 4-week intervention phase. Nine adults (mean age 33 ± 15.8 years; female, 89 %) completed the study. After using the AVS device for 4 weeks, significant improvement was seen in reported insomnia (ISI, p = 0.003), pain severity (BPI, p = 0.005), and pain interference with functioning (BPI, p = 0.001). Large effect sizes (Partial η2 0.20–0.94) (Cohen’s d 0.44–1.45) were observed. The results of this pilot study suggest that the AVS program may be efficacious in decreasing both insomnia and pain symptoms. In order to better assess the efficacy of AVS for sleep promotion and possible pain reduction, more definitive randomized controlled trials will be needed. These should include appropriate sample sizes, objective measures of sleep and pain, and longitudinal follow-up.  相似文献   

19.
We present a new classification of β-turns specific to antiparallel β-sheets based upon the topology of H-bond formation. This classification results from ONIOM calculations using B3LYP/D95** density functional theory and AM1 semiempirical calculations as the high and low levels, respectively. We chose acetyl(Ala)(6)NH(2) as a model system as it is the simplest all-alanine system that can form all the H-bonds required for a β-turn in a sheet. Of the 10 different conformations we have found, the most stable structures have C(7) cyclic H-bonds in place of the C(10) interactions specified in the classic definition. Also, the chiralities specified for residues i + 1 and i + 2 in the classic definition disappear when the structures are optimized using our techniques, as the energetic differences among the four diastereomers of each structure are not substantial for 8 of the 10 conformations.  相似文献   

20.
A field study was carried out in 18 herds with loose housing of pregnant sows (loose herds) and in 18 herds with tethered or stalled pregnant sows (confined herds). Three of the loose herds were excluded due to different kind of flooring from the rest of the herds. The remaining 15 herds had partly slatted concrete floors and electronic sow feeding. The frequencies of sows with vulva and body lesions, thin sows as well as the culling reasons and production results were used as animal welfare indicators for the herds. Vulva lesions were found only in the loose herds and the mean prevalence proportion of sows with lesions within these herds was 15.2%. All vulva lesions observed in this study seemed to be caused by biting. The relative risk of vulva lesions was 2.6 times higher in the loose herds with no roughage feeding as compared to loose herds with appetite feeding of roughage. The sows in the loose herds, that had a feeding station with a mechanical hind gate had 1.8 greater risk of vulva lesions than sows in the loose herds that used a feeding station with an electronic gate. The mean prevalence proportion of sows with body lesions was 13.1% in the loose herds and 4.0% in the confined herds. Aggression between sows seemed to be the main cause of body lesions in the loose herds, while decubitus ulcers on the shoulders were the main cause of body lesions in the confined herds. Sows in loose herds that were not fed additional roughage feeding had 1.7 times greater risk of body lesions than sows in herds that used additional roughage feeding. The main culling reasons and production results were similar in the loose and confined herds. This study showed that there were welfare problems both in confined and loose herds, however, with improved management, many of the welfare problems associated with loose housing can be reduced.  相似文献   

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