[Waiting time to transcatheter aortic valve implantation (TAVI) and mortality during wait period in Algeria]. / Délais d'attente d'implantation de valve aortique transcutanée (TAVI) et mortalité durant la période d'attente en Algérie.

BACKGROUND: Trans Aortic Valve Implantation (TAVI) has become the primary treatment for aortic stenosis in patients over 75 years old. Despite its clinical efficacy, it's adoption in emerging countries remains low due to the high cost of prostheses and limited healthcare funding resources. This leads to prolonged waiting times for the TAVI procedure, which may lead to complications; these data are missing particularly in emerging countries. AIMS: To describe waiting time for TAVI and mortality rate in this waiting period. MATERIALS AND METHODS: This was prospective registry, patients referred for TAVI were prospectively followed; waiting time was calculated from the first visit after referral to TAVI implantation, clinical and, call fellow up was performed every 3 months. We divided patients into two groups: Group 1 (G1) patients still awaiting TAVI (105 patients), and those who underwent TAVI (36 patients). Group 2 (G2) patients who died while awaiting TAVI (16 patients, 10,2 %). RESULTS: Demographic characteristics were similar, with a tendency for older age in G2 (79.5 ± 5.7 years vs. 82.5 ± 7.4 years, p=0,06). G2 exhibited more left ventricular ejection fraction (LVEF) impairment (8.5% vs. 25%, p=0,03) and a higher rate of severe heart failure with dyspnea stages III or IV (2.8% vs. 12.5%, p<0,001). The mean follow-up in G1 was 242.9 ± 137.4 days; the waiting time for TAVI was 231.7 ± 134.1 days, and the average time between the first consultation and death while awaiting TAVI (G2) was 335.1 ± 167.4 days. CONCLUSION: in our series, waiting time is high due to limited Trans aortic heart valve availability, mortality during this wait exceeds 10%. Adverse prognostic factors include impaired LVEF and severe dyspnea stages III or IV.

Silver nanoparticle embedded copper oxide as an efficient core-shell for the catalytic reduction of 4-nitrophenol and antibacterial activity improvement.

A facile and eco-friendly method was developed to prepare a microporous CuO@Ag0 core-shell with high catalytic and antibacterial activities. Scanning and transmission electron microscopy revealed a preponderance of nearly spherical 50 nm particles with slight structure compaction. Comparison of the hysteresis loops confirmed the structure compaction after AgNP incorporation, and a significant decrease of the specific surface area from 55.31 m2 g-1 for CuO to 8.03 m2 g-1 for CuO@Ag0 was noticed. A kinetic study of 4-nitrophenol (4-NP) reduction into 4-aminophenol (4-AP) with sodium borohydride revealed a first order reaction that produces total conversion in less than 18 minutes. CuO@Ag0 also exhibited appreciable antibacterial activity against Staphylococcus aureus. The antibacterial effects were found to strongly depend on the size, contact surface, morphology and chemical composition of the catalyst particles. The addition of Ag0-NPs produced more reactive oxygen species in the bacteria medium. These results open promising prospects for its potential applications as a low cost catalyst in wastewater treatment and antibacterial agent in cosmetics.

Synthesis and properties of ZnO-HMD@ZnO-Fe/Cu core-shell as advanced material for hydrogen storage.

In this paper, a new synthetic strategy towards functionalized ZnO-HMD@ZnO-Fe/Cu core-shell using sol-gel process modified by chemical grafting of hexamethylenediamine (HMD) on the core and in-situ dispersion of Cu0/Fe0 as metallic nanoparticles (M-NPs) on the shell. The as-prepared core-shell materials were fully characterized by transmission electron microscopy, X-ray powder diffractometry, diffuse reflectance and FT-IR spectrophotometery, photoluminescence, and complexes impedance spectroscopy measurements. The XRD patterns agreed with that of the ZnO typical wurtzite structure, indicating good crystallinity of ZnO-HMD@ZnO-Fe/Cu, with the presence of Fe0 and Cu0 phases. Hexamethylenediamine grafting and M-NPs insertion were highly activated and enhanced the core and shell interface by the physiochemical interaction. After functionalization, luminescence intensities and electrical properties of both core and core-shell nanoparticles are improved, indicating the effects of the surface groups on the charge transfer of ZnO-HMD@ZnO-Fe/Cu. The hydrogen capacity retention was depended strongly on the composition and structure of the obtained core-shell. Iron/Copper-loaded ZnO-HMD@ZnO materials exhibited the highest capacity for hydrogen storage. The excellent stability and performance of the ZnO-HMD@ZnO-Fe/Cu core-shell make it an efficient candidate for hydrogen storage.

Continuous solid-phase extraction and gas chromatography-mass spectrometry determination of pharmaceuticals and hormones in water samples.

A semi-automatic flow-based method for the simultaneous determination of 9 pharmaceuticals and 3 hormones in water samples in a single analytical run is proposed. The analytes were retained on a solid-phase extraction sorbent column and 1 microL of the eluate analysed by gas chromatography in combination with electron impact ionization mass spectrometry in the SIM mode. The sorbent used, Oasis-HLB, provided near-quantitative recovery of all analytes. The proposed method was validated with quite good analytical results including low limits of detection (0.01-0.06 ng L(-1) for 100 mL of water) and good linearity (r2>0.993) throughout the studied concentration ranges. The method provided good accuracy (recoveries of 85-103%) and precision (between- and within-day RSD values less than 7%) in the determination of the pharmaceuticals and hormones in tap, river, pond, well, swimming pool and wastewater.

Management of diabetic foot lesions in hospital: costs and benefits.

OBJECTIVE: The aim of this study was to evaluate the direct and indirect costs associated with diabetic-related foot lesions in patients hospitalized in a department of Endocrinology and Diabetology (36 beds). MATERIAL AND METHODS: Direct costs included costs associated with hospital stay, laboratory testing, medical and surgical treatment. Lesions were classified in 3 groups (I, II, III) according to their importance (Wagner classification). RESULTS: Among 1,779 admissions for diabetes, 163 (i.e., 9.16%) were related to a foot lesion. The stay in hospital for these lesions reached 7,247 days over a 5-year period, with an average stay duration of 45 days per lesion. Mean length of hospital stay varied according to the importance of the lesion: 26.87 days, 48.25 days, 57.12 days for group I, II and III, respectively. The total cost amounted to 914,534.39 US dollars and the mean cost 5,610.64 US dollars. Mean cost was 3,326.76, 5,712.24, 7,399.74 US dollars for group I, II and III, respectively. Nearly 80% of the financial costs were due to hospital stay. Primary healing occurred in 59.09% of the patients (n=78); 17.4% (n=23) of the patients required major amputation, 14.4% (n=19) minor amputation. Death rate reached 9.1% (n=12). CONCLUSION: An increase in length of stay and costs with importance of the lesion was identified. The strategy of care of the diabetic lesions should be based upon the prevention of ulcer formation: it seems actually the best mean (the least expensive) in a developing country where financial resources are very limited. This prevention should be made through regular patient education, appropriately fitted shoes, and regular careful examination by a General Practitioner or a Diabetologist.

Diabetic foot lesions: etiologic and prognostic factors.

The clinical characteristics of 132 diabetic patients referred for treatment of foot lesions were surveyed. One hundred and sixty three lesions (n=163) concerned 88 men and 44 women during a five-year period (from January 1989 to December 1993). Hospitalisation rate equalled 9.16%, i.e. 11.17% for men and 6.82% for women (p <0.001); the men/women ratio was 1.64. Eighty nine per cent (89%) of patients presented type 2 diabetes and 11% of patients type 1 diabetes. Mean age at the first foot lesion was 59.64 +/- 11.74 years. The mean duration of diabetes was 10.95 +/- 6.80 years. The patients had a high prevalence of diabetic complications, particularly peripheral neuropathy (84.85%) and obvious peripheral arteriopathy (78.78%). Infection was almost constant. There was no significant difference between men and women as far as the prevalence of complications was concerned. Smoking habits were noticed only in men. Inadequate footwear was considered as the major exogenous risk factor leading to a foot lesion. The definitive results 6 months after hospitalisation were as follows: the death rate was 9.09% (n=2; 11 men and 1 women, NS); 15.90% of patients (n=12) underwent a major amputation (4 at the level of the thigh, 17 at the level of the leg), 14.39% of patients (n=19) underwent a minor amputation; in 59.09% of patients (n=78) there was no amputation. Two patients (1.51%) underwent two consecutive amputations, left hospital against medical advice during their second hospitalisation, and then were lost sight. The prevalence of foot lesions was more important in men. Moreover, seriousness of the lesions and consequently the rate of amputations were important in men; this was probably due to smoking habits. The factors that influence the outcome seem to be: male gender, delay of management, quality of medical treatment, surgical attitude, inadequate level of amputation and finally lack of structured prevention. Prevention then should be based on the patient's education, general practitioners' training and a better and more efficient cooperation between surgeons and diabetologists.

Absorption spectrophotometry.

A review is given of the development of spectrophotometers from the earliest models to the latest microprocessor instruments with photodiode detection systems.