Recent advances in PVA-polysaccharide based hydrogels and electrospun nanofibers in biomedical applications: A review.

Among several types of carbohydrate polymers blend PVA hydrogel membranes used for biomedical applications in particular wound dressings; electrospun nanofibrous membranes have gained increased interest because of their extraordinary features e.g. huge surface area to volume ratio, high porosity, adequate permeability, excellent wound-exudates absorption capacity, architecture similarity with skin ECM and sustained release-profile over long time. In this study, modern perspectives of synthesized/developed electrospun nanofibrous hydrogel membranes based popular carbohydrate polymers blend PVA which recently have been employed for versatile biomedical applications particularly wound dressings, were discussed intensively and compared in detail with traditional fabricated membranes based films, as well. Clinically relevant and advantages of electrospun nanofibrous membranes were discussed in terms of their biocompatibility and easily fabrication and functionalization in different biomedical applications.

Dual-Heteroatom-Doped Reduced Graphene Oxide Sheets Conjoined CoNi-Based Carbide and Sulfide Nanoparticles for Efficient Oxygen Evolution Reaction.

Intensive research is being conducted into highly efficient and cheap nanoscale materials for the electrocatalytic oxidation of water. In this context, we built heterostructures of multilayered CoNi-cyanide bridged coordination (CoNi-CP) nanosheets and graphene oxide (GO) sheets (CoNi-CP/GO) as a source for heterostructured functional electrodes. The layered CoNi-CP/GO hybrid components heated in nitrogen gas (N2) at 450 °C yield CoNi-based carbide (CoNi-C) through thermal decomposition of CoNi-CP, while GO is converted into reduced GO (rGO) to finally form a CoNi-C/rGO-450 composite. The CoNi-C/rGO-450 composite shows a reasonable efficiency for oxygen evolution reaction (OER) through water oxidations in alkaline solution. Meanwhile, regulated annealing of CoNi-CP/GO in N2 with thiourea at 450 and 550 °C produces CoNi-based sulfide (CoNi-S) rather than CoNi-C between rGO sheets co-doped by nitrogen (N) and sulfur (S) heteroatoms (NS-rGO) to form CoNi-S/NS-rGO-450 and CoNi-S/NS-rGO-550 composites, respectively. The CoNi-S/NS-rGO-550 shows the best efficiency for electrocatalytic OER among all electrodes with an overpotential of 290 mV at 10 mA cm-2 and a Tafel slope of 79.5 mV dec-1. By applying the iR compensation to remove resistance of the solution (2.1 Ω), the performance is further improved to achieve a current density of 10 mA cm-2 at an overpotential of 274 mV with a Tafel slope of 70.5 mV dec-1. This result is expected to be a promising electrocatalyst compared to the currently used electrocatalysts and a step for fuel cell applications in the future.

A review on polymeric hydrogel membranes for wound dressing applications: PVA-based hydrogel dressings.

This review presents the past and current efforts with a brief description on the featured properties of hydrogel membranes fabricated from biopolymers and synthetic ones for wound dressing applications. Many endeavors have been exerted during past ten years for developing new artificial polymeric membranes, which fulfill the demanded conditions for the treatment of skin wounds. This review mainly focuses on representing specifications of ideal polymeric wound dressing membranes, such as crosslinked hydrogels compatible with wound dressing purposes. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite or hybrid hydrogel membranes to achieve the typical wound dressing requirements.

Clinical indications for Gallium-68 positron emission tomography imaging.

BACKGROUND: (68)Ga-PET imaging is showing slow but steady progress when compared to (18)F-FDG PET. The advantage of in-house preparation of (68)Ga without necessity of a cyclotron, and the new generator configuration with future possibility of freeze-dried kits would make it a promising PET agent for the future. METHODS: An exhaustive literature exploration was performed using the search engines High-Wire Press, Pubmed, Embase and library databases. Recent reviews on the subject and up-to-date studies on the topic were found that described the role of (68)Ga-PET imaging. Clinical experiences, including our own are described. RESULTS: Recent resurgence in development of peptides labelled with radiometals, for diagnostic and therapeutic purposes, resulted in a new beginning for (68)Ga-PET imaging. Pre-clinical experience employing animal models and investigation of tracer kinetics/tumour uptake measurements using dynamic (68)Ga-PET have provided data regarding identification of Somatostatin receptors subtypes on many tumours. Present published experiences including our own support these and highlight current clinical utility of (68)Ga-PET imaging. (68)Ga-DOTATOC and (68)Ga-DOTANOC are the most prominent radiopharmaceuticals used nowadays. CONCLUSION: (68)Ga-PET is employed in the management of neuroendocrine tumours and neural crest tumours (phaeochromocytoma and paraganglioma) with diagnostic and therapeutic implications where it compliments present radiologic and scintigraphic procedures. Diagnosis and radiotherapy treatment planning for meningiomas in pertinent clinical setting is another potential use of (68)Ga-PET. Limited studies have shown its utility in prostate cancer but further studies are contemplated. Therefore, current experience tends to open a new horizon for the clinical utility of (68)Ga-PET imaging in future.

Value of myocardial SPECT in early detection of ischaemia in children with sickle cell anaemia.

BACKGROUND: Cardiovascular complications of sickle cell anaemia (SCA) are relatively infrequent compared with other cerebral and skeletal insults. However, myocardial infarction and cardiac dysfunction have been reported in autopsied patients with SCA. When left ventricular functional parameters of gated SPECT and echocardiography were compared incidentally in children with SCA, some 26% of patients were found to have evident myocardial ischaemia. This stimulated the current work with the aim to further analyse these incidental findings and evaluate the possible role of SPECT in early detection of coronary insufficiency in children with SCA. PATIENTS AND METHODS: Twenty-seven patients (19 girls, 8 boys), mean age 9.2±4.2 years, with SCA were examined by baseline ECG, echocardiography and gated SPECT. They were all free from any cardiac symptoms. Intravenous injection of 5 to 10 mCi 99MTc-MIBI or 99MTc-Myoview was administered, according to the predetermined weight-dependent paediatric dose. Stress SPECT was obtained 45 to 60 minutes after tracer injection, which took place at peak physical exercise (6 patients) or 3 to 4 minutes after IV infusion of dipyridamole pharmacological stress (21 patients). Rest SPECT study was acquired 4 to 5 hours later after a second injection of 99MTc-MIBI/Myoview. A semiquantitative nine-segment stress/rest bull's eye model was used to assess to the presence/extent of myocardial ischaemia. RESULTS: Myocardial perfusion was normal in 20 patients (74%). Seven patients (26%) had significant perfusion defects in the stress images. Four of them showed perfusion defect in one or two segments. Complete reversibility in the rest study was seen in all patients. Two patients showed a mixture of reversible and fixed perfusion defects in four segments. One patient had evident left ventricular dilatation with multiple fixed and reversible defects (cardiomyopathy). In this case, a diffusely reduced myocardial wall contractility was seen and a low LVEF of 42% as assessed by echocardiography. This was the only case showing agreement between the echo and SPECT findings. In the whole cohort the EF% and FS% by echocardiography were 61.7±5.9% and 33.2±3.4% respectively (mean±SD). There were no significant relations between myocardial perfusion abnormalities when compared with EF% and FS%; (p>0.05). CONCLUSION: Cardiac involvement in the form of myocardial ischaemia should be regarded as a high-risk complication in patients with SCA. Myocardial perfusion scintigraphy succeeded in the early detection of myocardial perfusion abnormalities in patients with SCA.

The relation between Trichomonas vaginalis and contraceptive measures.

PIP: The relationship between the incidence of trichomonas vaginalis and the use of oral contraceptive (OC) pills was observed in 100 females from the outpatient clinic of Cairo University Hospital. 50 patients took the OC Anovlar and 50 used a size 3 Lippes Loop. 2 sample discharges were analyzed before contraceptive use, i.e. 1 wet smear on a clean slide and the other cultured on Trichosol trypticase serum medium (STS) composed of Trypticase 20 gm, cysteine Hcl 1 1/2 gm, maltose 1 gm, agar 1 gm, methylene blue .003 gm, chloamphenicol .1 gm, and distilled water 950 ml. These 2 analyses were repeated at 1, 3, and 6 months after OC use. The findings indicate the presence of trichomonas vaginalis in 36% of OC users at 3 months and 58% at 6 months, at a significant level of .05 and .01. Before use it was 2%. The Lippes Loop users has 0% before use and 6% at 3 and 6 months at .05 level of significance. The results coincide with other reported results.^ieng