Prevalence and predictors of gestational diabetes mellitus: a nationwide multicentre prospective study.

AIM: Prevalence rates of gestational diabetes mellitus (GDM) show considerable variation among different countries and regions of the world. The primary aim of this study was to determine the nationwide prevalence and predictors of GDM in Turkey. METHODS: We conducted prospective nationwide screening among pregnant women. Between August 2016 and November 2017, a total of 2643 pregnant women from 51 centres in 12 different regions were enrolled. A two-step screening method and Carpenter and Coustan criteria were used in the diagnosis of GDM. Clinical and biochemical data were obtained using electronic database software. RESULTS: The national prevalence of GDM was found to be 16.2% [95% confidence intervals (CI) 15.0% to 17.4%] without a significant difference between urban and rural regions. Women with GDM were older (mean age: 32 ± 5 vs. 28 ± 5 years, P < 0.001) and heavier (mean BMI: 27.2 ± 5.1 vs. 24.7 ± 4.7 kg/m2 , P < 0.001) than their counterparts without GDM. The prevalence of GDM tended to increase with age (< 25 years, 6.9%; 26-35 years, 15.6%; and 36-45 years, 32.7%; P < 0.001). Maternal age, maternal BMI, history of previous GDM and family history of diabetes mellitus were independent predictors of developing GDM (P < 0.05 for all). Low-risk women (age < 25 years, BMI < 25 kg/m2 , no family history of diabetes) comprised 10.7% of the total population and the prevalence of GDM in these women was 4.5% (95% CI 2.4% to 7.8%). CONCLUSION: The results of this nationwide study indicate that GDM is very common, affecting one in seven pregnancies in Turkey. Implementation of international guidelines on screening and management of this public health problem is required.

COBALAMIN C DEFICIENCY WITH INFANTILE SPASM AND CUTANEOUS FINDINGS: A UNIQUE CASE.

Cobalamin C (CbIC) deficiency is a rare disorder of vitamin B12 metabolism which results from impaired conversion of both its active forms methylcobalamin and adenosylcobalamin. Early onset cblC typically presents in the first year of life with hypotonia, lethargy, seizures, microcephaly, hydrocephalus, developmental delay and other multisystem involvement including hematologic, ocular, renal, hepatic and cardiac symptoms. We report a case of a female infant with cblC deficiency who presented with seizures, developmental delay and hypopigmented cutaneous lesions. To our knowledge, the patient is the first diagnosed with cblC deficiency who had skin hypopigmentation.

REVERSIBLE CLINICAL AND MAGNETIC RESONANCE IMAGING FINDINGS IN LATE-ONSET COBALAMIN C DEFECT.

Cobalamin C (Cbl C) disease is an inborn error of intracellular cobalamin metabolism. Two distinct clinical types are defined according to the age of onset. We describe an 8 year old girl with late-onset Cbl C disease presenting with neuropsychiatric symptoms. Mutation analysis revealed homozygous c.394C>T (p.R132X) mutation in the MMACHC gene. Serial magnetic resonance imaging (MRI) before and after the treatment are provided. MRI of the brain before treatment showed bilateral patchy focal hyperintensities in the white matter and cortical atrophy. After treatment with intramuscular hydroxycobalamin, oral folinic acid, oral betaine, normalization of MRI findings can be achieved in addition to clinical improvement. We present this case to draw attention to the reversibility of clinical and MRI findings in the late onset Cbl C disease after treatment.

A rare mutation in EIF2B4 gene in an epileptic child with vanishing white matter disease: a case report.

A 12-month old boy presented with intractable seizures present since 3-month of age. He had, previously, been admitted numerous times to the pediatric emergency room for intractable and prolonged seizures during the course of his disease. Differential diagnosis was made to exclude several inborn metabolic disorders, including vitamin B6 deficiency, biotinidase deficiency and nonketotic hyperglycinemia. Although the initial brain MRI revealed a mild cerebral and cerebellar white matter involvement, follow-up images showed diffuse cerebral and cerebellar white matter dysmyelination, progressive rarefaction and cystic degeneration. A genetic analysis was performed for vanishing white matter (VWM) disease and a homozygote c. 1091G>A mutation was detected at the EIF2B4 gene. This case emphasizes the fact that VWM disease may present with refractory seizures since early infancy.

Color Doppler analysis of female reproductive vasculature in Behçet's disease.

Behçet's disease (BD) may affect female reproductive vasculature. We aimed to evaluate Doppler sonographic characteristics of female reproductive vasculature and also ovarian volume, endometrial thickness (EMT) and antral follicle count of BD patients in comparison with a healthy control group. Seventeen premenopausal women aged between 18-45 years with BD, and a control group of 31 age- and body mass index-matched healthy women was included in the study. Uterine, spiral and intraovarian artery blood flow were examined by Doppler sonography in the late follicular phase. Resistance index, pulsatility index and systolic/diastolic ratio were recorded together with ovarian volume, EMT and antral follicle count. In particular this is a pilot study including the evaluation of the spiral and uterine arteries in BD. Doppler sonographic parameters, ovarian volume, EMT and antral follicle count of BD patients and healthy controls were not found to be statistically different. As a result of our analysis, we found similar Doppler sonographic features of both BD patients and the control group. Further studies conducted on a larger sample population with more aggressive BD symptoms may reveal the actual effect of BD on the female reproductive system.

Assessment of hygiene habits and attitudes among removable partial denture wearers in a university hospital.

AIMS: The aim of this study was conducting a survey of hygiene habits and use of removable partial dentures (RPDs) and correlate them with the social conditions of the interviewees. METHODS: A total of 145 RPD wearers were interviewed by experienced clinical staff using a structured questionnaire. A Chi-squared test was performed to evaluate statistical significance between the variables, and the level of significance was P<0.05. RESULTS: A total of 72 (49%) patients reported that they had not been well informed by the dentists. Brushing was the most frequent cleaning method (57.6%). 77 (53.1%) patients did not take off their dentures at night. The frequency of cleaning dentures and using cleansing tablet was significantly higher in females than in males (P<0.05). The frequency of denture cleaning, cleaned parts of denture, use of cleansing tablet, removal of dentures at night, frequency of tooth brushing, does not show any significant difference according to age, educational status or duration of denture usage (P>0.05). RPD wearers did not clean their dentures and natural teeth satisfactorily and had limited knowledge of denture cleansing and oral hygiene maintenance. CONCLUSIONS: Hygiene habits and attitudes may be affected by gender, but education level and hygiene attitudes may not always present positive correlation. Dentists should thoroughly inform patients about the harmful effects of overnight wearing and motivate to clean metal parts of RPD's and cleansing tablet use in order to minimize the abrasive effect of widely preferred cleaning method of brushing with toothpaste.

Low prevalence of growth hormone deficiency in Turkish patients with Hashimoto's thyroiditis.

BACKGROUND: Hashimoto's Thyroiditis (HT) is frequently isolated, but may also be associated with other autoimmune disorders. Autoimmune hypophysitis can result in growth hormone deficiency (GHD). Various prevalences of GHD have been reported in HT in several different ethnic populations. AIM: The aim of this study was assessing the prevalence of GHD in Turkish population with HT. MATERIALS AND METHODS: Two hundred twenty-seven (208 females and 19 males, mean age 40.1 ± 10.8 years, range 18-64 years) patients with euthyroid HT were included. RESULTS: All patients were euthyroid with or without T4 treatment (median TSH 2.2 mIU/L, range 0.2-4.2 mIU/L; median FT4 15.6 pmol/L, range 12-22 pmol/L; and median FT3 4.5 pmol/L, range 3.0-6.2 pmol/L), and median TPO-Ab was 817 IU/mL (range 63 to >3,000). One hundred and thirty-six of them were using medications including L-thyroxine (59.9 %). Insulin-like growth factor-I (IGF-I) levels of 210 patients (92.5 %) were normal. Glucagon stimulation testing in 17 subjects revealed GHD (peak <3 mcg/L) in two subjects. We then performed insulin tolerance test (ITT) to both of them as the gold standard confirmatory test. One patient had no GH response to ITT, either. Our data reveal the prevalence of GHD (based on low IGF-I and ITT result) in this particular group of Turkish HT patients as 0.4 %. CONCLUSION: We conclude that the isolated GHD is rarely observed in HT in our population. The prevalence of GHD is 0.4 % in this particular group of Turkish HT patients suggesting that routine investigation of GHD is not mandatory.

Cell Staining Microgels Derived from a Natural Phenolic Dye: Hematoxylin Has Intriguing Biomedical Potential.

Hematoxylin (HT) as a natural phenolic dye compound is generally used together with eosin (E) dye as H&E in the histological staining of tissues. Here, we report for the first time the polymeric particle preparation from HT as poly(Hematoxylin) ((p(HT)) microgels via microemulsion method in a one-step using a benign crosslinker, glycerol diglycidyl ether (GDE). P(HT) microgels are about 10 µm and spherical in shape with a zeta potential value of -34.6 ± 2.8 mV and an isoelectric point (IEP) of pH 1.79. Interestingly, fluorescence properties of HT molecules were retained upon microgel formation, e.g., the fluorescence emission intensity of p(HT) at 343 nm was about 2.8 times less than that of the HT molecule at λex: 300 nm. P(HT) microgels are hydrolytically degradable and can be controlled by using an amount of crosslinker, GDE, e.g., about 40%, 20%, and 10% of p(HT) microgels was degraded in 15 days in aqueous environments for the microgels prepared at 100, 200, and 300% mole ratios of GDE to HT, respectively. Interestingly, HT molecules at 1000 mg/mL showed 22.7 + 0.4% cell viability whereas the p(HT) microgels exhibited a cell viability of 94.3 + 7.2% against fibroblast cells. Furthermore, even at 2000 mg/mL concentrations of HT and p(HT), the inhibition% of α-glucosidase enzyme were measured as 93.2 ± 0.3 and 81.3 ± 6.3%, respectively at a 0.03 unit/mL enzyme concentration, establishing some potential application of p(HT) microgels for neurogenerative diseases. Moreover, p(HT) microgels showed two times higher MBC values than HT molecules, e.g., 5.0 versus 2.5 mg/mL MIC values against Gram-negative E. coli and Gram-positive S. aureus, respectively.

Effect of lumbar puncture in patients with aneurysmal subarachnoid hemorrhage treated microsurgically or endovascularly.

OBJECTIVE: The aim of this study was to evaluate the effect of treatment modality (surgical clipping vs. endovascular coiling) and lumbar puncture (LP) in patients with aneurysmal subarachnoid hemorrhage (SAH) based on neurologic status on admission and clinical outcome. PATIENTS AND METHODS: One hundred forty-eight consecutive patients with ruptured intracranial aneurysms treated via endovascular or surgical methods were included in our study. Patients who refused further therapy or received only supportive therapy because of bad neurologic status were excluded. Severity of SAH was evaluated using the Fisher score. World Federation of Neurosurgical Societies (WFNS) and Hunt and Hess (H&H) scores were used for evaluation of neurologic status. Glasgow Outcome Scale scores and modified Rankin scores were used for outcome evaluation. RESULTS: We found that modified Rankin scores were significantly lower in the surgical clipping group (1.1 ± 1.4) than in the endovascular coiling group (1.7 ± 1.8) (p: 0.04). The positive lumbar puncture [LP(+)] group had similar outcome scores as the negative lumbar puncture [LP(-)] group, although the LP(+) group had worse initial SAH evaluation scores (WFNS 1.64 ± 0.95-1.23 ± 0.61, p: 0.0004 and H&H 2.18 ± 1.07-1.65 ± 0.88, p: 0.001). CONCLUSION: Surgical clipping might improve clinical outcome better than endovascular coiling, although a more confident conclusion requires absolute randomization of patients for both treatments. LP could also improve clinical outcome in patients with high initial SAH evaluation scores.

Effect of exercise on appetite-regulating hormones in overweight women.

Over the past decade, our knowledge of how homeostatic systems regulate food intake and body weight has increased with the discovery of circulating peptides such as leptin, acyl ghrelin, des-acyl ghrelin and obestatin. These hormones regulate the appetite and food intake by sending signals to the brain regarding the body's nutritional status. The purpose of this study was to investigate the response of appetite-regulating hormones to exercise. Nine overweight women undertook two 2 h trials in a randomized crossover design. In the exercise trial, subjects ran for 60 min at 50% of maximal oxygen uptake followed by a 60 min rest period. In the control trial, subjects rested for 2 h. Obestatin, acyl ghrelin, des-acyl ghrelin and leptin concentrations were measured at baseline and at 20, 40, 60, 90 and 120 min after baseline. A two-way ANOVA revealed a significant (P < 0.05) interaction effect for leptin and acyl ghrelin. However, changes in obestatin and des-acyl ghrelin concentration were statistically insignificant (P > 0.05). The data indicated that although acute treadmill exercise resulted in a significant change in acyl ghrelin and leptin levels, it had no effect on plasma obestatin and des-acyl ghrelin levels.

Prediction of mortality and the development of critical illness in the course of COVID-19 with tertiary hospital data: vaccines? Critical illness scores? Mortality scores?

OBJECTIVE: Even though COVID-19 affects some risk groups more severely than others, there are still unknowns concerning the intensive care procedure and death in non-risk categories, making it vital to identify critical sickness and fatality risk factors at this time. The purpose of this study was to look into the efficacy of critical illness and mortality scores, as well as other risk factors in COVID-19. PATIENTS AND METHODS: Two hundred twenty-eight inpatients diagnosed with COVID-19 were included in the study. Sociodemographic, clinical, and laboratory data were recorded and risk calculations were made with the help of web-based patient data-based calculation programs called COVID-GRAM Critical Illness and 4C-Mortality score. RESULTS: The median age of 228 patients included in the study was 56.5 years, 51.3% of them were males, and ninety-six (42.1%) were unvaccinated. According to the multivariate analysis, the factors affecting the development of critical illness were cough [odds ratio=0.303, 95% CI (0.123,0.749), p=0.010], creatinine [odds ratio=1.542, 95% CI (1.100, 2.161), p=0.012], respiratory rate [odds ratio=1.484, 95% CI (1.302, 1.692), p=0.000], COVID-GRAM Critical Illness Score [odds ratio=3.005, 95% CI (1.288, 7.011), p=0.011]. Factors affecting survival were vaccine status [odds ratio=0.320, 95% CI (0.127,0.802), p=0.015], blood urea nitrogen (BUN) [odds ratio=1.032, 95% CI (1.012, 1.053), p=0.002], respiratory rate [odds ratio=1.173, 95% CI (1.070, 1.285), p=0.001], COVID-GRAM-critical-illness score [odds ratio=2.714, 95% CI (1.123, 6.556), p=0.027]. CONCLUSIONS: The findings suggested that risk assessment might employ risk scoring, such as COVID-GRAM Critical Illness, and that immunization against COVID-19 will reduce the occurrence of mortality.

Safety and tolerability of first-line bevacizumab in metastatic colorectal cancer.

PURPOSE: To determine the clinical features of bevacizumab-associated toxicities in metastatic colorectal cancer (MCRC) patients. METHODS: The medical records of 60 patients with MCRC who were treated with chemotherapy including bevacizumab in the first-line setting were retrospectively evaluated. RESULTS: Bevacizumab was administered along with irinotecan plus 5-fluorouracil7sol;leucovorin (5-FU/LV) to 44 patients, 57horbar;FU7sol;LV+oxaliplatin to 8 patients, capecitabine+oxaliplatin to 6 patients and 5-FU/LV to 2 patients. The total number of the cycles received was 381 (median 6, range 17horbar;13). The most common bevacizumab-related toxicity was grade 1-2 bleeding (28%) followed by hypertension (17%). Grade 1-2 proteinuria was seen in 8% of the patients (no grade 3-4 proteinuria). Arterial thromboembolic events (ATE) were not observed, however 3 patients (5%) had experienced grade 3-4 venous thromboembolic events. In 3 patients (5%) grade 1-2 wound complications were seen (delayed wound healing in the place of the venous access device in 2, and wound infection in 1). In addition, gastrointestinal perforation (GIP) was seen in 3 (5%) patients. Two of the patients were treated by surgical intervention and one patient died of sepsis. CONCLUSION: Bevacizumab is well tolerated when combined with various chemotherapy regimens. As bevacizumab is becoming widely used in the routine oncology practice, further studies which investigate the mechanism of bevacizumab-associated toxicities are warranted to develop effective management strategies for these adverse events.

Role of mandibular anatomical structures in sexual dimorphism in Turkish population: a radiomorphometric CBCT study.

Sex determination is one of the primary concerns of forensic science. The cranial bones, pelvis, and mandible have been used for determining the sex of specimens. Because the mandible is robust and sexually dimorphic, studies have evaluated its metric and morphological traits. This study was designed as a retrospective study involving cone beam computed tomography (CBCT) images to assess sexual dimorphism of the mandible in the Turkish population. Total sample group consisted of 176 bimaxillary CBCT scans (71 males and 102 females; ages 19-67 years). Sixteen mandibular parameters were measured using two different software programmes. Measurements were recorded in various planes of three-dimensional (3D) reconstructions of the scans. All parameters aside from SIMaCD were found to be statistically significant. The highest diagnostic accuracy rate was associated with IMaF, and the overall accuracy rate of the fourteen parameters was found to be 80%.

Comparison of 2017 ILAE and Semiological seizure classifications before and after video-EEG monitoring in childhood epilepsy.

OBJECTIVE: Our aim in this study is to evaluate epilepsy classification in children with epilepsy before monitoring (based on information received from the family) and after monitoring (based on video-EEG) by comparing two separate classification systems, namely the 2017 International League Against Epilepsy (ILAE) and Semiological Seizure Classification (SSC) systems. Classifications and methods were compared in terms of simplicity, intelligibility, and applicability during daily outpatient care. PATIENTS AND METHODS: The study was performed with 230 recorded seizures of 173 patients aged between 1 and 18 years who underwent video-EEG monitoring and clinical seizure recordings. Seizure types and video-EEG data of the patients were recorded. Seizures were first classified based on information obtained from the parents of the patients in interviews, recorded as "before video-EEG monitoring classification," and a second characterization, based on video EEG-monitoring, was subsequently recorded as "after video-EEG monitoring classification". The consistency of both seizure classifications was evaluated. RESULTS: For both classifications, autonomic seizures were the least congruent seizures (κ=0.27, κ=-0.005). The families generally described the seizures very well; the consistency before and after video-EEG monitoring was good. Focal seizures with impaired awareness were most common in the 2017 ILAE classification (κ=0.6), while for the SSC simple motor seizures were most common (κ=0.84). Among subtypes, clonic-tonic seizures were the most common, and the second most common subtype was dialeptic (κ=0.67). Overall, the harmony between the SSC and ILAE systems was good. The rate of good and excellent coefficients of concordance for both the SSC and 2017 ILAE was determined as 77.8% for the expanded SSC, 48% for the 2017 ILAE, 71.4% for the basic SSC, and 60% for the 2017 ILAE. CONCLUSIONS: In practice, it is difficult to determine seizure patterns reliably in cases of childhood epilepsy. Parents, however, can generally describe seizures very well. Although the SSC seems to be superior, both the SSC and 2017 ILAE systems can be applied in daily use. Such classification enables the rise of new concepts and a better understanding of disease groups. The continuing development of classification systems will lead to advancements for patients.

Electrical status epilepticus during sleep (ESES) in benign childhood epilepsy with Centrotemporal spikes (BCECTS): insights into predictive factors, and clinical and EEG outcomes.

OBJECTIVE: Benign childhood epilepsy with centro-temporal spikes (BCECTS), otherwise known as benign rolandic epilepsy, is the most common focal epilepsy in childhood. This study aimed to evaluate the development and resolution of ESES in children with BCECTS and evaluate the clinical and electroencephalography (EEG) parameters associated with prognosis. PATIENTS AND METHODS: Resolution of ESES was defined as the reduction of the spike-wave index (SWI) to <50%. The SWI short method, measurements from the first 180 s of non-rapid eye movement; and the conventional method, measurements from total NREM stage 2, SW count during the first 60 and 180 s of NREM, SW localization, and ESES type were determined. RESULTS: Of a total of 126 BCECTS patients, 33, including 13 females, 20 males, who developed ESES during follow-up, were included in the study. ESES remission was observed in 42.4% (n = 14) of the patients. The median time to remission was 10.5 months. The rate of resolution was 87.9 % for the entire population. The mean age at resolution was 9.8 ± 2.05 years and the mean time to resolution was 8.8 months. CONCLUSIONS: The data demonstrated that age at ESES diagnosis, the time between BCECTS diagnosis and the onset of ESES, time to resolution of ESES, ESES remission, and seizure freedom after ESES were significantly associated with prognosis. The early recognition of ESES evolution in children with BECTS, the better understanding of the relationship between age at ESES diagnosis and remission and prognosis, and timely intervention can prevent long-term sequelae.

Safety, Efficacy, and Durability of Stent-Assisted Coiling Treatment of M2 (Insular) Segment MCA Aneurysms.

BACKGROUND AND PURPOSE: Most distal MCA aneurysms are located within the insular segment, which lies between the limen insulae and circular sulcus. However, experience is limited in the microsurgical and endovascular management of insular segment MCA aneurysms. In this multicenter retrospective case series, we aimed to investigate the safety, efficacy, and durability of stent-assisted coiling for treatment of insular segment MCA aneurysms. MATERIALS AND METHODS: A retrospective review was performed to identify patients with insular MCA aneurysms that were treated with stent-assisted coiling. The technical success of the procedures and the initial and follow-up clinical and angiographic outcomes were assessed. Periprocedural and delayed complications were reviewed. RESULTS: Twenty-seven aneurysms in 27 patients with a mean age of 53.3 (SD,11.3) years were included. The mean size of the aneurysms was 6.3 (SD 2.6) mm. Endovascular procedures were successfully performed in all patients. Immediate postprocedural angiography revealed complete aneurysm occlusions in 81.5%. Periprocedural complications developed in 7.4% without causing permanent morbidity. A delayed thromboembolic complication resulted in a minor permanent morbidity in 1 patient (3.7%). There was no mortality. The mean duration of angiographic follow-up was 19.5 (SD, 9.8) months. The last follow-up examinations showed complete occlusion in 92.6%. During the follow-up period, none of the treated aneurysms showed recanalization. CONCLUSIONS: The results of this study demonstrate that stent-assisted coiling with a low-profile self-expandable stent is a feasible and relatively safe technique for endovascular treatment of insular segment complex MCA aneurysms. Additionally, it provides an effective and durable treatment for insular MCA aneurysms.

Chondroitin Sulfate-Based Cryogels for Biomedical Applications.

Cryogels attained from natural materials offer exceptional properties in applications such as tissue engineering. Moreover, Halloysite Nanotubes (HNT) at 1:0.5 weight ratio were embedded into CS cryogels to render additional biomedical properties. The hemolysis index of CS cryogel and CS:HNT cryogels was calculated as 0.77 ± 0.41 and 0.81 ± 0.24 and defined as non-hemolytic materials. However, the blood coagulation indices of CS cryogel and CS:HNT cryogels were determined as 76 ± 2% and 68 ± 3%, suggesting a mild blood clotting capability. The maximum% swelling capacity of CS cryogel was measured as 3587 ± 186%, 4014 ± 184%, and 3984 ± 113%, at pH 1.0, pH 7.4 and pH 9.0, respectively, which were reduced to 1961 ± 288%, 2816 ± 192, 2405 ± 73%, respectively, for CS:HNT cryogel. It was found that CS cryogels can hydrolytically be degraded 41 ± 1% (by wt) in 16-day incubation, whereas the CS:HNT cryogels degraded by 30 ± 1 wt %. There is no chelation for HNT and 67.5 ± 1% Cu(II) chelation for linear CS was measured. On the other hand, the CS cryogel and CS:HNT cryogel revealed Cu(II) chelating capabilities of 60.1 ± 12.5%, and 43.2 ± 17.5%, respectively, from 0.1 mg/mL Cu(II) ion stock solution. Additionally, at 0.5 mg/mL CS, CS:HNT, and HNT, the Fe(II) chelation capacity of 99.7 ± 0.6, 86.2 ± 4.7% and only 11.9 ± 4.5% were measured, respectively, while no Fe(II) was chelated by linear CS chelated Fe(II). As the adjustable and controllable swelling properties of cryogels are important parameters in biomedical applications, the swelling properties of CS cryogels, at different solution pHs, e.g., at the solution pHs of 1.0, 7.4 and 9.0, were measured as 3587 ± 186%, 4014 ± 184%, and 3984 ± 113%, respectively, and the maximum selling% values of CS:HNT cryogels were determined as 1961 ± 288%, 2816 ± 192, 2405 ± 73%, respectively, at the same conditions. Alpha glucosidase enzyme interactions were investigated and found that CS-based cryogels can stimulate this enzyme at any CS formulation.

Adaptive tuning of infrared emission using VO2 thin films.

Phase-transition materials provide exciting opportunities for controlling optical properties of photonic devices dynamically. Here, we systematically investigate the infrared emission from a thin film of vanadium dioxide (VO2). We experimentally demonstrate that such thin films are promising candidates to tune and control the thermal radiation of an underlying hot body with different emissivity features. In particular, we studied two different heat sources with completely different emissivity features, i.e. a black body-like and a mirror-like heated body. The infrared emission characteristics were investigated in the 3.5-5.1 µm spectral range using the infrared thermography technique which included heating the sample, and then cooling back. Experimental results were theoretically analyzed by modelling the VO2 film as a metamaterial for a temperature range close to its critical temperature. Our systematic study reveals that VO2 thin films with just one layer 80 nm thick has the potential to develop completely different dynamic tuning of infrared radiation, enabling both black-body emission suppression and as well as mirror emissivity boosting, in the same single layer device. Understanding the dynamics and effects of thermal tuning on infrared emission will benefit wide range of infrared technologies including thermal emitters, sensors, active IR filters and detectors.

Natural Celluloses as Catalysts in Dehydrogenation of NaBH4 in Methanol for H2 Production.

Cellulose, the most abundant renewable biopolymer, exists in many forms, such as microgranular cellulose (MGCell), sigmacell cellulose (SCell), cellulose fibers (FCell), and α-cellulose (AlfaCell). Several of these cellulose forms were protonated with an amine-containing agent polyethyleneimine (PEI), and the modified celluloses (XCell-PEI+) were studied as catalysts in methanolysis of NaBH4 for hydrogen (H2) generation. It was found that the SCell-PEI+-catalyzed reaction is the fastest one among the modified celluloses with a hydrogen generation rate of 5520 ± 119 mL H2/(g of catalyst × min). The activation energies of MGCell-PEI+, SCell-PEI+, FCell-PEI+, and AlfaCell-PEI+ were determined as +21.7, +23.4, +24.8, and + 21.8 kJ/mol, respectively. Reusability of catalysts was investigated, and regeneration of cellulose based catalysts after the fifth cycle could be readily achieved by HCl treatment to completely recover its activity. Therefore, PEI-modified-protonated cellulose forms constitute sustainable, re-generable, and renewable catalysts for production of H2, an environmentally benign green energy carrier.

Ecosystem-based fisheries management forestalls climate-driven collapse.

Climate change is impacting fisheries worldwide with uncertain outcomes for food and nutritional security. Using management strategy evaluations for key US fisheries in the eastern Bering Sea we find that Ecosystem Based Fisheries Management (EBFM) measures forestall future declines under climate change over non-EBFM approaches. Yet, benefits are species-specific and decrease markedly after 2050. Under high-baseline carbon emission scenarios (RCP 8.5), end-of-century (2075-2100) pollock and Pacific cod fisheries collapse in >70% and >35% of all simulations, respectively. Our analysis suggests that 2.1-2.3 °C (modeled summer bottom temperature) is a tipping point of rapid decline in gadid biomass and catch. Multiyear stanzas above 2.1 °C become commonplace in projections from ~2030 onward, with higher agreement under RCP 8.5 than simulations with moderate carbon mitigation (i.e., RCP 4.5). We find that EBFM ameliorates climate change impacts on fisheries in the near-term, but long-term EBFM benefits are limited by the magnitude of anticipated change.