A heterostructural MoS2QDs@UiO-66 nanocomposite for the highly efficient photocatalytic degradation of methylene blue under visible light and simulated sunlight.

The development of recyclable photocatalysts with high activity and stability has piqued the interest of researchers in the field of wastewater treatment. In this study, an ultrasonic probe approach was used to immerse a sequence of heterojunctions formed by metal-organic frameworks (UiO-66) and different amounts of molybdenum disulfide quantum dots (MoS2QDs), resulting in a highly recyclable MoS2QDs@UiO-66 photocatalyst. Multiple advanced techniques, such as XPS, XRD, TEM, XRF, and UV-vis spectrophotometry, were used to characterize and confirm the successful preparation of UIO-66 impregnated with MoS2QDs. The results indicated that the best heterostructure catalyst exhibited superior efficiency in the photocatalytic degradation of methylene blue (MB) in water, achieving approximately 99% removal within 30 minutes under simulated sunlight, while approximately 97% removal under visible light. The outstanding photocatalytic performance is predominantly attributed to the photoinduced separation of carriers in this heterostructure system. This study proposes a unique, simple, and low-cost method for improving the degradation performance of organic contaminants in water.

Mesoscopic engineering materials for visual detection and selective removal of copper ions from drinking and waste water sources.

The monitoring and removal of abundant heavy metals such as Cu ions are considerable global concerns because of their severe impact on the health of humans and other living organisms. To meet this global challenge, we engineered a novel mesoscopic capture protocol for the highly selective removal and visual monitoring of copper (Cu2+) ions from wide-ranging water sources. The capture hierarchy carriers featured three-dimensional, microsized MgO mesoarchitecture rectangular sheet-like mosaics that were randomly built in horizontal and vertical directions, uniformly arranged sheet faces, corners, and edges, smoothly quadrilateral surface coverage for strong Cu2+-to-ligand binding exposure, and multidiffusible pathways. The Cu2+ ion-selectively active captor surface design was engineered through the simple incorporation/encapsulation of a synthetic molecular chelation agent into hierarchical mesoporous MgO rectangular sheet platforms to produce a selective, visual mesoscopic captor (VMC). The nanoscale VMC dressing of MgO rectangular mosaic hierarchy by molecularly electron-enriched chelates with actively double core bindings of azo- and sulfonamide- groups and hydrophobic dodecyl tail showed potential to selectively trap and efficiently remove ultratrace Cu2+-ions with an extreme removal capability of ~233 mg/g from watery solutions, such as drinking water, hospital effluent, and food-processing wastewater at specific pH values. In addition to the Cu2+ ion-selective removal, the VMC design enabled the continuous visual monitoring of ultratrace Cu2+ ions (~3.35 × 10-8 M) as a consequence of strong chelate-to-Cu2+ binding events among all accumulated matrices in water sources. Our experimental recycle protocol provided evidence of reusability and recyclability of VMC (≥10 cycles). With our mesoscopic capture protocol, the VMC can be a promising candidate for the selective decontamination/removal and sensitive detection of hazardous inorganic pollutants from different water sources with indoor or outdoor applications.

Preparation of Pickering emulsions stabilized by metal organic frameworks using oscillatory woven metal micro-screen.

Uniform Pickering emulsions stabilized by metal organic frameworks (MOFs) MIL-101 and ZIF-8 nanoparticles (NPs) were successfully prepared using an oscillatory woven metal microscreen (WMMS) emulsification system in the presence and the absence of surfactants. The effects of operating and system parameters including the frequency and amplitude of oscillation, the type of nano-particle and/or surfactant on the droplet size and coefficient of variance of the prepared emulsions are investigated. The results showed that both the hydrodynamics of the system and the hydrophobic/hydrophilic nature of the NP influenced the interfacial properties of the oil-water interface during droplet formation and after detachment, which in turn affected the final droplet size and distribution. Comparison between the measured and predicted droplet size using a simple torque balance (TB) model is discussed.

Androgen receptor-CAG repeats in infertile Egyptian men.

This study aimed to assess the androgen receptor (AR) codon amino acids glutamine (CAG) repeats in 185 Egyptian men divided into fertile controls (n = 30), oligoasthenoteratozoospermic (OAT) men (n = 35), nonobstructive azoospermic (NOA) men (n = 120; 18 successful testicular sperm extraction (TESE) and 102 unsuccessful TESE cases). They were subjected to history taking, genital examination, semen analysis, testicular biopsies for NOA cases, serum hormones and CAG repeats by PCR. The mean AR-CAG repeats showed significant difference between NOA group compared with fertile controls or OAT groups. Nonsignificant difference was elicited between OAT group and fertile controls. In NOA cases, CAG repeats demonstrated nonsignificant difference between unsuccessful and successful TESE. AR-CAG repeats elicited significant negative correlation with sperm count, significant positive correlation with sperm normal forms percentage and nonsignificant correlations with sperm motility per cent, tested serum hormones or testicular volume. It is concluded that AR-CAG repeats in Egyptian infertile men are in the range of other international or regional studies. AR-CAG repeats have demonstrated nonsignificant difference regarding TESE outcome in NOA cases.

Effect of C-factor on microtensile bond strengths of low-shrinkage composites.

UNLABELLED: This study evaluated the microtensile bond strength (µ-TBS) of low-shrinkage composites with their corresponding adhesive systems, Filtek Silorane/Silorane adhesive (SIL, 3M ESPE AG, Seefeld, Germany) and Aelite LS/One-Step Plus (AL, BISCO Inc, Schaumburg, IL, USA) in cavities with different C-factors. Filtek Z250/Adper Single Bond Plus (Z, 3M ESPE, St Paul, MN, USA) was used as a control. METHOD: Standardized Class I cavities were prepared in extracted human molars after removing occlusal enamel. Cavities were assigned into six different C-factors by applying nail polish to four walls, three walls, two walls adjacent to each other, two walls opposite to each other, one wall, or no walls. Resin composites with their corresponding adhesive systems were applied according to manufacturer instructions. Specimens were sectioned to obtain four rectangular beams from the center of the restorations and µ-TBS was measured. Data were analyzed by Weibull survival analysis. Shrinkage stresses of the resin composites were determined after 30 minutes from the start of light-curing using a tensometer testing machine. Flexure elastic modulus was determined using standard procedures, in accordance with ISO 4049. Data for shrinkage stress and elastic modulus were analyzed by one-way analysis of variance followed by a Tukey multiple-comparisons test (p<0.05). RESULTS: µ-TBS of both SIL and AL were not affected by different C-factors; however, the bond strength of Z decreased significantly when the C-factor increased. Shrinkage stress results were 0.94 ± 0.1, 1.79 ± 0.18, and 2.14 ± 0.23 MPa for SIL, AL, and Z, respectively. The flexural modulus of both the SIL and the AL was significantly lower than that of Z. CONCLUSIONS: Increasing C-factor did not negatively affect the bond strength of low-shrinkage composites.

Diagnosis of human brucellosis in Egypt by polymerase chain reaction.

This study aimed to establish an accurate and sensitive polymerase chain reaction (PCR) technique for the diagnosis of active human brucellosis in Egypt. We failed to extract Brucella DNA with a commercial kit, but an extraction kit designed in-house using 2 sets of primers [B4/B5 (223 bp) and JPF/JPR (193 bp)] was successful and more economical. The technique showed high sensitivity, specificity and accuracy. The PCR positivity increased significantly with increasing seropositivity titres by the standard tube agglutination test and showed 100% positivity in patients with positive blood cultures. We recommend using PCR as an alternative to culture for diagnosis of brucellosis.

Diagnosis of human brucellosis in Egypt by polymerase chain reaction

This study aimed to establish an accurate and sensitive polymerase chain reaction [PCR] technique for the diagnosis of active human brucellosis in Egypt. We failed to extract Brucella DNA with a commercial kit, but an extraction kit designed in-house using 2 sets of primers [B4/B5 [223 bp] and JPF/JPR [193 bp]] was successful and more economical. The technique showed high sensitivity, specificity and accuracy. The PCR positivity increased significantly with increasing seropositivity titres by the standard tube agglutination test and showed 100% positivity in patients with positive blood cultures. We recommend using PCR as an alternative to culture for diagnosis of brucellosis

Surveillance of antibacterial resistance in Staphylococcus aureus isolated in Kuwaiti hospitals.

OBJECTIVE: To investigate the prevalence of antibiotic resistance among Staphylococcus aureus isolated in Kuwaiti hospitals. MATERIALS AND METHODS: S. aureus were isolated and identified following standard microbiological methods. Antibacterial susceptibility test was performed by disk diffusion and the measurement of minimum inhibitory concentration with E-test strips. RESULTS: A total of 1,846 S. aureus isolates were analyzed from 13 hospitals between 1 March and 30 October 2005. They were isolated from 1,765 (95.6%) inpatients and 81 (4.4%) outpatients. Methicillin resistance was detected in 588 (32.0%) of the isolates. The methicillin-resistant S. aureus (MRSA) consisted of 461 (78%) multiresistant and 127 (22%) nonmultiresistant isolates. The nonmultiresistant MRSA consisted of epidemic MRSA-15 and community-associated MRSA. The community-associated MRSA was detected in all hospitals with MRSA, indicating its establishment in Kuwaiti hospitals. The proportion of isolates resistant to gentamicin, kanamycin, erythromycin, tetracycline, ciprofloxacin, fusidic acid and trimethoprim was higher among MRSA than methicillin-susceptible S. aureus (MSSA) isolates. Twenty-four and 22% of MRSA and MSSA isolates, respectively, expressed reduced susceptibility to vancomycin (minimum inhibitory concentration = 3-4 mg/l). CONCLUSION: The study revealed the presence of methicillin resistance in 32% of S. aureus isolated in Kuwaiti hospitals and revealed an increase in the number of MRSA and MSSA with reduced susceptibility to vancomycin.

Marginal adaptation of Class 5 composite restorations: retention grooves versus enamel and dentin bonding.

Microleakage was assessed in class 5 composite resin restorations placed in extracted noncarious human premolar teeth. The occlusal enamel cavo-surface margins of the class 5 cavity preparations had been beveled and etched with phosphoric acid gel for 30 seconds. The teeth were divided into four equal groups. The first group was only restored with the composite filling material, while in the second group, a mechanically cut undercut grooves were done before restoration. In the third group, a dentin bonding agent was used before restoration, while in the fourth group, the dentin bonding agent was used in conjunction with undercut grooves. The restored teeth were placed in methylene blue dye, invested and sectioned. The extent of dye penetration along the tooth-restoration interface was compared. The group restored in cavities with undercut grooves alone showed the greatest leakage. Leakage was statistically significantly greater than in the groups restored in conjunction with dentin bonding. The tooth restoration interface at the gingival margin showed severe leakage than did at the occlusal margin.

Effect of different post-cure heat-treatment methods on the dimensional stability of a visible-light cured-composite inlays.

A total number of 50 rectangular specimens, made of hybrid visible light cured composite were used in the present study. The specimens were divided into 5 groups (10 specimens each). Each group was treated with one of the post-cure heat-treatment methods. It was found that, the specimens exposed to the normal post-cure heat-treatment method demonstrated the minimum dimensional change values (0.62%, 0.166%, 1.4% and 2.23%) for length, width, and volume respectively. On the other hand, the specimens exposed to the (delay-heat) water ageing method displayed the maximum values (2.9%, 0.56%, 9.2%, and 9.98%) for the length, width, height, and volume respectively.