Recent developments in the instrumentation and data analysis of synchrotron small‐angle X‐ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular ...tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small‐ and wide‐angle X‐ray scattering (SAXS–WAXS or SWAXS). The endstation features an in‐vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size‐exclusion chromatography system incorporating several optical probes including a UV–Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS–WAXS data collection and data reduction for high‐throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal‐model fittings to the data in the q range ∼0.005–2.0 Å−1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration‐dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.
A new endstation for biological small‐ and wide‐angle X‐ray scattering is detailed, which provides development opportunities for studying correlated local and global structures of biomolecules in solution.
Background and purpose
Elevated plasma total homocysteine level (tHcy) is associated with increased risk of dementia via increased white matter changes or reduction in cortical volume. Whether tHcy ...has an independent impact on regional perfusion and if it can predict a more rapid cognitive decline in mild Alzheimer dementia (AD) warrants investigation.
Methods
Eighty AD patients with a clinical dementia rating of 1 were enrolled. Their Cognitive Ability Screening Instrument (CASI) scores on enrolment and after 1 year of follow‐up as well as their perfusion index (PI) from single photon emission computed tomography upon enrolment were analyzed.
Results
In cross‐sectional analysis, elevated tHcy was associated with lower frontal PI independent of cerebrovascular risk factors (β = −0.35, P = 0.009). The CASI scores correlated with temporo‐parietal PI (Pearson r range 0.3–0.39, P < 0.01) but not with tHcy or frontal PI. By longitudinal analysis, only tHcy level was related to a more rapid cognitive decline (odds ratio for executive function score 1.82; odds ratio for total CASI score 1.74).
Conclusions
Cognitive performance in mild AD can be reflected by hypo‐perfusion of the temporo‐parietal region while frontal hypo‐perfusion may be mediated by tHcy. tHcy level is an independent risk factor for rapid cognitive decline, especially in the executive function.
Summary
Background
Cirrhotic patients admitted to intensive care units (ICUs) have high mortality rates. The Chronic Liver Failure–Sequential Organ Failure Assessment (CLIF‐SOFA) score, a modified ...Sequential Organ Failure Assessment (SOFA) score, is a newly developed scoring system exclusively for patients with end‐stage liver disease.
Aim
To externally validate the efficacy of the CLIF‐SOFA score and evaluate other scoring systems for 6‐month mortality in critically ill cirrhotic patients.
Methods
This study prospectively recorded and analysed the data for 30 demographical parameters and some clinical characteristic variables on day 1 of 250 cirrhotic patients admitted to a 10‐bed specialised hepatogastroenterology ICU in a 2000‐bed tertiary care referral hospital during the period from September 2010 to August 2013.
Results
The overall in‐hospital and 6‐month mortality rate were 58.8% (147/250) and 78.0% (195/250), respectively. Liver diseases were mostly attributed to hepatitis B virus infection (32%). Multiple Cox logistic regression hazard analysis revealed that Glasgow coma scale, both the CLIF‐SOFA and Acute Physiology and Chronic Health Evaluation III (ACPACHE III) scores determined on the first day of ICU admission were independent predictors of 6‐month mortality. Analysis of the area under the receiver operating characteristic curve revealed that the CLIF‐SOFA score had the best discriminatory power (0.900 ± 0.020). Moreover, the cumulative 6‐month survival rates differed significantly for patients with a CLIF‐SOFA score ≤11 and those with a CLIF‐SOFA score >11 on the ICU admission day.
Conclusion
Both CLIF‐SOFA and APACHE III scores are excellent prognosis evaluation tools for critically ill cirrhotic patients.
Caregivers play a major role in providing care for patients with Alzheimer's disease (AD) and are themselves at higher risk of health comorbidities.
To address the impact of neuropsychiatric symptoms ...of patients in different stages of AD on their caregivers' burden.
This prospective study enrolled 260 AD patients with clinical dementia rating (CDR) of 0.5, 1 and 2 at a tertiary medical center.
All patients were tested using the mini-mental state examination (MMSE), the cognitive abilities screening instrument (CASI), the neuropsychiatric inventory (NPI) and the CDR scale. Data regarding therapeutic outcomes of anti-Alzheimer's drugs were also collected. Caregivers were tested using NPI.
The mean follow-up interval was 25.0 ± 12.2 months, and two patients died during follow-up. NPI-burden was positively correlated with NPI-sum ( r = 0.822, P < 0.001) but negatively correlated with years of education ( r = -0.140, P = 0.024), CASI score ( r = -0.259, P < 0.001) and MMSE score ( r = -0.262, P <0.001). Multiple linear regression analysis showed that only NPI-sum was independently associated with mean NPI-burden. Both higher mean CASI and MMSE scores had better therapeutic outcome of anti-Alzheimer's drugs ( P = 0.001 and P = 0.005, respectively).
The severity of neuropsychiatric symptoms in patients with AD was positively associated with caregiver's stress, and patients with better cognitive functions, under treatment with anti-Alzheimer's drugs, had better therapeutic outcomes. To reduce the impact of neuropsychiatric symptoms, it is crucial to detect dementia in its early phases and provide early intervention with anti-Alzheimer's drugs, which might help decrease the caregiver burden, thereby improving their quality of life.
The optical design and performance of the recently opened 13A biological small‐angle X‐ray scattering (SAXS) beamline at the 3.0 GeV Taiwan Photon Source of the National Synchrotron Radiation ...Research Center are reported. The beamline is designed for studies of biological structures and kinetics in a wide range of length and time scales, from angstrom to micrometre and from microsecond to minutes. A 4 m IU24 undulator of the beamline provides high‐flux X‐rays in the energy range 4.0–23.0 keV. MoB4C double‐multilayer and Si(111) double‐crystal monochromators (DMM/DCM) are combined on the same rotating platform for a smooth rotation transition from a high‐flux beam of ∼4 × 1014 photons s−1 to a high‐energy‐resolution beam of ΔE/E ≃ 1.5 × 10−4; both modes share a constant beam exit. With a set of Kirkpatrick–Baez (KB) mirrors, the X‐ray beam is focused to the farthest SAXS detector position, 52 m from the source. A downstream four‐bounce crystal collimator, comprising two sets of Si(311) double crystals arranged in a dispersive configuration, optionally collimate the DCM (vertically diffracted) beam in the horizontal direction for ultra‐SAXS with a minimum scattering vector q down to 0.0004 Å−1, which allows resolving ordered d‐spacing up to 1 µm. A microbeam, of 10–50 µm beam size, is tailored by a combined set of high‐heat‐load slits followed by micrometre‐precision slits situated at the front‐end 15.5 m position. The second set of KB mirrors then focus the beam to the 40 m sample position, with a demagnification ratio of ∼1.5. A detecting system comprising two in‐vacuum X‐ray pixel detectors is installed to perform synchronized small‐ and wide‐angle X‐ray scattering data collections. The observed beamline performance proves the feasibility of having compound features of high flux, microbeam and ultra‐SAXS in one beamline.
The optical design and performance of the BioSAXS beamline at the Taiwan Photon Source are reported
This study investigated seasonal variations in the mass concentration and chemical composition of ambient aerosols observed at three stations (coastal, mountainous, and downtown sites) in northern ...Taiwan from March 2009 to February 2012. The results show that the major aerosol components include ammonium, sulfate, nitrate, sea salt, dust, organic carbon, and elemental carbon, whereas the mass fraction of each species depends on the sampling location and season. A significant correlation (r = 0.7–0.8) was observed in aerosol concentrations measured at the respective stations, indicating that aerosol concentrations were dominated by regional‐scale factors. Ammonium, sulfate, and nitrate consistently reached respective peak values in the spring in conjunction with dust particle levels. This shows that the transport of dust and particulate air pollutants from the Asian continent has affected the atmospheric environment in this area. Distinct seasonality was observed for sea salt and secondary organic carbon (SOC): sea salt levels peaked in the autumn, whereas SOC levels peaked in the summer, implying that their sources were regulated by independent seasonal factors. Correlation between sea salt concentration and surface wind speed was derived from coastal measurements and showed a high value for the wind speed sensitivity parameter of around 0.37 for our location. In addition, it was revealed that the SOC concentration in aerosols was positively correlated with oxidant photolysis index (Ox × UVB), suggesting that the SOC seasonality was dominated by hydroxyl radical production.
Key Points
Inorganic particulate pollutants and dust consistently peaked in the spring due to Asian outflow effects
Ambient concentrations of sea salt particles were exponentially correlated with surface wind speeds
The production of secondary organic aerosols was dominated by the photolysis of total oxidants
Postprocedural infections by Mycobacterium abscessus complex are increasing worldwide, and the source and route of transmission are infrequently identified. Here the extension of a previous ...clustering of paediatric patients with surgical site infections due to a single strain of the subspecies M. massiliense is reported. The investigation was conducted at a 2200-bed teaching hospital in Taiwan and included microbial surveillance of the environment (water, air, equipment and supplies) and a case–control study. We performed molecular identification and typing of the isolates by a trilocus sequencing scheme, confirmed by multilocus sequencing typing and pulsed-field gel electrophoresis. We investigated 40 patients who developed postprocedure soft tissue or bloodstream infections by M. massiliense (TPE101) during a 3-year period. Thirty-eight patients were identified at hospital A, and one newborn and her mother were identified at hospital B (185 km from hospital A). A case–control study identified the association of invasive procedures (adjusted odds ratio, 9.13) and ultrasonography (adjusted odds ratio, 2.97) (both p <0.05) with acquiring the outbreak strain. Isolates from the cases and unopened bottles of ultrasound transmission gel were all of strain ST48 and indistinguishable or closely related by pulsed-field gel electrophoresis. After replacement of contaminated gel, no new cases were detected during 18 months' follow-up. This investigation identified the use of contaminated gel as the common source causing an outbreak on a larger scale than had been recognized. Our findings halted production by the manufacturer and prompted revision of hospital guidelines.
Current methods of chemical vapour deposition (CVD) of graphene on copper are complicated by multiple processing steps and by high temperatures required in both preparing the copper and inducing ...subsequent film growth. Here we demonstrate a plasma-enhanced CVD chemistry that enables the entire process to take place in a single step, at reduced temperatures (<420 °C), and in a matter of minutes. Growth on copper foils is found to nucleate from arrays of well-aligned domains, and the ensuing films possess sub-nanometre smoothness, excellent crystalline quality, low strain, few defects and room-temperature electrical mobility up to (6.0±1.0) × 10(4) cm(2) V(-1) s(-1), better than that of large, single-crystalline graphene derived from thermal CVD growth. These results indicate that elevated temperatures and crystalline substrates are not necessary for synthesizing high-quality graphene.
The associated risk of phthalate exposure, both parent compounds in the home and their metabolites in urine, to childhood allergic and respiratory morbidity, after adjusting for exposures of indoor ...pollutants, especially bioaerosols, was comprehensively assessed. Levels of five phthalates in settled dust from the homes of 101 children (3–9 years old) were measured, along with their corresponding urinary metabolites. Other environmental risk factors, including indoor CO2, PM2.5, formaldehyde, 1,3‐β‐d‐glucan, endotoxin, allergen and fungal levels, were concomitantly examined. Subject’s health status was verified by pediatricians, and parents recorded observed daily symptoms of their children for the week that the home investigation visit took place. Significantly increased level of benzylbutyl phthalate, in settled dust, was associated with test case subjects (allergic or asthmatic children). Higher levels of dibutyl phthalate and its metabolites, mono‐n‐butyl phthalate, and mono‐2‐ethylhexyl phthalate were found to be the potential risk factors for the health outcomes of interest. Similarly, indoor fungal exposure remained a significant risk factor, especially for reported respiratory symptoms. The relative contribution from exposure to phthalates and indoor biocontaminants in childhood allergic and respiratory morbidity is, for the first time, quantitatively assessed and characterized.
Practical Implications
For asthmatic and allergic children living in subtropical and highly developed environments like homes in Taiwan, controlling environmental exposure of phthalates may be viewed as equally important as avoiding indoor microbial burdens, for the management of allergy‐related diseases. It is also recognized that multidisciplinary efforts will be critical in realizing the true underlying mechanisms associated with these observations.
Background and purpose
Restless legs syndrome (RLS) is an underestimated movement disorder in patients with end‐stage renal disease (ESRD). Several clinical and laboratory factors were inconsistently ...reported to associate with RLS. We aim to perform a large‐scale multicenter study to investigate the possible associated risk factors of RLS in patients with ESRD in Taiwan, a country with the highest incidence of uremia in the world.
Methods
From October 2009 to October 2011, we constitutively recruited 1130 patients with ESRD from 17 hemodialysis centers. Demographic, laboratory data, presence and severity of RLS were collected. Odds ratios (ORs) were estimated by logistic regression models.
Results
We found the prevalence of RLS to be 25.3% in patients with ESRD. Having type 2 diabetes OR = 3.61 (2.27–5.77), P < 0.01, low serum transferrin saturation OR = 1.42 (1.01–2.03), P < 0.05 and duration of dialysis OR = 1.09 (1.03–1.14), P < 0.01 were associated with RLS. In contrast, high serum hemoglobin level was inversely associated with RLS OR = 0.61 (0.40–0.89), P < 0.05. RLS has a significant impact on sleep quality in dialysis patients. Among patients with RLS, history of type 2 diabetes OR = 4.04 (1.65–10.79), P < 0.05, low serum hemoglobin level OR = 5.41 (2.43–13.12), P < 0.01 and duration of dialysis OR = 1.01 (1.01–1.02), P < 0.01 were associated with increased severity of RLS.
Conclusions
Our findings demonstrated that RLS is common in Taiwanese dialysis patients. Clinicians should have a high suspicion for the presence of RLS symptoms in patients with ESRD, especially those with type 2 diabetes, anemia, low serum iron status and long duration of dialysis.
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