Recent developments in voltammetric and amperometric sensors for cysteine detection

This review article aims to provide an overview of the recent advances in the voltammetric and amperometric sensing of cysteine (Cys). The introduction summarizes the important role of Cys as an essential amino acid, techniques for its sensing, and the utilization of electrochemical methods and chemically modified electrodes for its determination. The main section covers voltammetric and amperometric sensing of Cys based on glassy carbon electrodes, screen printed electrodes, and carbon paste electrodes, modified with various electrocatalytic materials. The conclusion section discusses the current challenges of Cys determination and the future perspectives.

This review article aims to provide an overview of the recent advances in the voltammetric and amperometric sensing of cysteine (Cys).     

First principles study on structural,electronic and optical properties of HfS2(1−x)Se2x and ZrS2(1−x)Se2x ternary alloys

Alloying 2D transition metal dichalcogenides (TMDs) with dopants to achieve ternary alloys is as an efficient and scalable solution for tuning the electronic and optical properties of two-dimensional materials. This study provides a comprehensive study on the electronic and optical properties of ternary HfS_2(1−x)Se_2(x) and ZrS_2(1−x)Se_2(x) [0 ≤ x ≤ 1] alloys, by employing density functional theory calculations along with random phase approximation. Phonon dispersions were also obtained by using density functional perturbation theory. The results indicate that both of the studied ternary families are stable and the increase of Selenium concentration in HfS_2(1−x)Se_2(x) and ZrS_2(1−x)Se_2(x) alloys results in a linear decrease of the electronic bandgap from 2.15 (ev) to 1.40 (ev) for HfS_2(1−x)Se_2(x) and 1.94 (ev) to 1.23 (ev) for ZrS_2(1−x)Se_2(x) based on the HSE06 functional. Increasing the Se concentration in the ternary alloys results in a red shift of the optical absorption spectra such that the main absorption peaks of HfS_2(1−x)Se_2(x) and ZrS_2(1−x)Se_2(x) cover a broad visible range from 3.153 to 2.607 eV and 2.405 to 1.908 eV, respectively. The studied materials appear to be excellent base materials for tunable electronic and optoelectronic devices in the visible range.

Adding Selenium to HfS₂ and ZrS₂ two-dimensional materials allows tuning the optical properties in a wide visible spectrum that can be used in various electronic and optical applications, including solar cells.     

The use of split metatarsal osteocutaneous free flaps in palatal and alveolar defects

A series of seven osteomucosal defects of the palate were closed by split metatarsal osteocutaneous free flaps. All seven patients had successful closure of their defects with minimal facial scarring and insignificant donor site morbidity. This procedure, performed in one stage, avoids the use of previously compromised local tissues and improves the blood supply to the area, thereby enhancing the subsequent indicated reconstruction of other damaged structures.     

Molecular epidemiology of hepatitis delta virus (HDV) in Iran: A preliminary report

To identify hepatitis delta virus (HDV) genetic variability and its circulating genotypes amongst infected Iranian patients, 25 patients with positive anti‐HDV status from different parts of Iran were enrolled in this cross‐sectional study. A portion of the HDV delta antigen was amplified, sequenced, and subjected to molecular and phylogenetic analysis. Clinical features and virological markers were evaluated. HDV RNA could be detected in 88% of anti‐HDV positive cases (22 patients) with chronic hepatitis B virus (HBV) infection and liver cirrhosis. Phylogenetic analysis revealed that all Iranian patients were infected by genotype I (clade 1) of HDV, supported by a high bootstrap value (100%, 1,000 replicates). All HDV‐positive patients were coinfected with genotype D1 of HBV. No significant association was determined between demographic, clinical, and virological variables in the population studied. In conclusion, the present molecular epidemiology survey reveals that clade 1 of HDV is predominant among coinfected HBV patients in Iran. J. Med. Virol. 80:2092–2099, 2008. © 2008 Wiley‐Liss, Inc.     

The Dietary Inflammatory Index Is Associated with Low Muscle Mass and Low Muscle Function in Older Australians

Age-associated chronic, low grade systemic inflammation has been recognised as an important contributing factor in the development of sarcopenia; importantly, diet may regulate this process. This cross-sectional study examined the association of diet-related inflammation with components of sarcopenia. Participants (n = 809) aged 60–95 years from the Geelong Osteoporosis Study were studied. Body composition was measured by dual energy X-ray absorptiometry. In this study, low appendicular lean mass (ALM/height², kg/m²) was defined as T-score < −1 and low muscle function as Timed-Up-and-Go >10 s over 3 m (TUG > 10). Dietary inflammatory index (DII^®) scores, based on specific foods and nutrients, were computed using dietary data collected from a food frequency questionnaire. Associations between DII scores and low muscle mass and low muscle function, alone and combined, were determined using linear and logistic regression. After adjusting for covariates, higher DII score was associated with lower ALM/height² (β −0.05, standard error (SE) 0.02, p = 0.028), and higher natural log-transformed (ln) (TUG) (β 0.02, standard error 0.01, p = 0.035) and higher likelihood for these components combined (odds ratio 1.33, 95% confidence interval 1.05 to 1.69, p = 0.015). A pro-inflammatory diet, as indicated by higher DII score, is associated with lower muscle mass, poorer muscle function and increased likelihood for the combination of low muscle mass and low muscle function. Further studies investigating whether anti-inflammatory dietary interventions could reduce the risk of sarcopenia are needed.     

Osteoprotegerin in relation to type 2 diabetes mellitus and the metabolic syndrome in postmenopausal women

Osteoprotegerin (OPG) is an inhibitor of bone resorption. Circulating levels of OPG seem to be elevated in patients with cardiovascular disorders and diabetes. The relationship between OPG and the metabolic syndrome has never been studied in postmenopausal women. In a population-based study, 382 Iranian postmenopausal women were randomly selected. Cardiovascular risk factors, high-sensitivity C-reactive protein, and OPG were measured. The diabetes classification and the metabolic syndrome definition were based on the criteria of the American Diabetes Association and the National Cholesterol Education Program-Adult Treatment Panel III, respectively. The mean serum OPG level was higher in those with type 2 diabetes mellitus than those without diabetes (4.33 ± 1.70 vs 3.84 ± 1.76 pmol/L, P = .016). In multiple logistic regression analysis, type 2 diabetes mellitus showed a significant association with serum OPG levels when adjustments were made for age, high-sensitivity C-reactive protein, and cardiovascular risk factors (odds ratio = 2.21; confidence interval, 1.34-3.66; P = .002). No significant difference was found between the mean serum OPG levels of those with the metabolic syndrome and those without the metabolic syndrome. Mean OPG levels did not differ significantly between subjects with and without hypertension, dyslipidemia, glucose intolerance, or abdominal obesity according to the National Cholesterol Education Program-Adult Treatment Panel III criteria. In conclusion, circulating OPG levels are significantly associated with diabetes, independent of cardiovascular risk factors in postmenopausal women. However, OPG levels have no correlation with the metabolic syndrome or its components. Further studies are warranted to determine the pathophysiologic origin of elevated OPG in type 2 diabetes mellitus.     

Evaluation of transcutaneous electrical simulation to improve recovery from corneal hypoesthesia after LASIK

Purpose  To evaluate the efficacy, and safety of transcutaneous electrical stimulation (TES) to accelerate corneal nerve regeneration and improved recovery from corneal hypesthasia after laser-assisted in situ keratomileusis (LASIK). Setting  Khodadoust Eye Hospital, Shiraz, Fars, Iran Methods  This prospective, randomized, clinical study comprised 40 eyes of 20 patients scheduled to undergo bilateral LASIK. In each patient, one eye was randomly assigned to receive transcutaneous electrical stimulation (20 HZ) for 60 minutes, and the other eye allocated as control. Corneal sensitivity was measured using the Cochet-Bonnet esthesiometer in four areas outside and five areas inside the LASIK flap preoperatively, and at 1 day, 1 week, 1 month, and 3 months postoperatively. Best-corrected visual acuity and the incidence of adverse events were noted at each visit. Results  For all four points outside the LASIK flap, normal corneal sensitivity was maintained throughout the study; no significant difference was found between the study eyes and the control eyes at these points (P > 0.05). All points within the LASIK flap except the point closest to the hinge demonstrated profound corneal hypoesthesia at 1 day, 1 week, and 1 month postoperatively, with no differences noted between the control and study eyes (P > 0.05). After 3 months, points within the flap had statistically significantly better corneal sensitivity in the study group than in the control group (P < 0.05). Conclusions  Transcutaneous electrical stimulation significantly improves corneal sensitivity at 3 months after LASIK. This may be due to accelerated corneal nerve regeneration by electrical stimulation. None of the authors has any financial or proprietary interest in any material or method mentioned.     

Application of Advanced Nanomaterials for Kidney Failure Treatment and Regeneration

The implementation of nanomedicine not only provides enhanced drug solubility and reduced off-target adverse effects, but also offers novel theranostic approaches in clinical practice. The increasing number of studies on the application of nanomaterials in kidney therapies has provided hope in a more efficient strategy for the treatment of renal diseases. The combination of biotechnology, material science and nanotechnology has rapidly gained momentum in the realm of therapeutic medicine. The establishment of the bedrock of this emerging field has been initiated and an exponential progress is observed which might significantly improve the quality of human life. In this context, several approaches based on nanomaterials have been applied in the treatment and regeneration of renal tissue. The presented review article in detail describes novel strategies for renal failure treatment with the use of various nanomaterials (including carbon nanotubes, nanofibrous membranes), mesenchymal stem cells-derived nanovesicles, and nanomaterial-based adsorbents and membranes that are used in wearable blood purification systems and synthetic kidneys.