Designing a novel visible-light-driven heterostructure Ni–ZnO/S-g-C3N4 photocatalyst for coloured pollutant degradation

In this study, photocorrosion of ZnO is inhibited by doping Ni in the ZnO nanostructure and electron–hole recombination was solved by forming a heterostructure with S-g-C₃N₄. Ni is doped into ZnO NPs from 0 to 10% (w/w). Among the Ni-decorated ZnO NPs, 4% Ni-doped ZnO NPs (4NZO) showed the best performance. So, 4% Ni–ZnO was used to form heterostructure NCs with S-g-C₃N₄. NZO NPs were formed by the wet co-precipitation route by varying the weight percentage of Ni (0–10% w/w). Methylene blue (MB) was used as a model dye for photocatalytic studies. For the preparation of the 4NZO-x-SCN nanocomposite, 4NZO NPs were formed in situ in the presence of various concentrations of S-g-C₃N₄ (10–50% (w/w)) by using the coprecipitation route. The electron spin resonance (ESR) and radical scavenger studies showed that O₂⁻ and OH free radicals were the main reactive species that were responsible for MB photodegradation.

Ni-doped ZnO/S-g-C₃N₄ nanocomposites were formed as a novel heterostructure photocatalyst.     

Aortic valve neocuspidization for aortic regurgitation associated with ventricular septal defect

 Open in a separate windowOBJECTIVESDifferent methods of aortic valve repair have been described in the literature for aortic regurgitation (AR) associated with doubly committed subarterial ventricular septal defects. Our goal was to present our experience with aortic valve reconstruction of a single leaflet using the aortic valve neocuspidization technique in this subset of patients.METHODSIt is a retrospective review of 7 patients with doubly committed subarterial ventricular septal defects with significant (>moderate) AR who underwent the single-leaflet neocuspidization technique of aortic valve reconstruction from January 2016 to January 2019. Data were collected from medical records. All patients had thorough 2-dimensional echocardiographic assessment preoperatively and during the follow-up period. Primary end points were freedom from postoperative AR and freedom from reoperation and all-cause mortality within the follow-up period with secondary end points of freedom from thromboembolism and infective endocarditis.RESULTSOut of 7 patients, 6 were male and 1 was female. There were no perioperative deaths. The mean follow-up period was 2.6 ± 0.8 years. No deaths occurred during the follow-up period. At the latest follow-up examination, only 2 patients showed mild AR and were asymptomatic. There was no documented event of infective endocarditis or thromboembolism during the follow-up period.CONCLUSIONSThe aortic leaflet neocuspidization procedure for the aortic valve is a relatively new concept. Availability of a template makes it an easily reproducible valve repair in paediatric patients with a single-leaflet abnormality. This technique preserves the remaining 2 normal leaflets, thus promoting the growth potential while maintaining near normal aortic root complex dynamics.     

Acute epiploic appendagitis mimicking symptoms of urinary tract infection: A diagnostic enigma in the emergency department

The epiploic appendages (also known as appendices epiploicae) are usually located on the anti‐mesenteric surface of the colon, extending from the caecum to the rectosigmoid, and epiploic appendagitis (EA) is the inflammation of these appendages. We report a clinical image of epiploic appendagitis creating a diagnostic challenge.     

Microbubble drug conjugate and focused ultrasound blood brain barrier delivery of AAV-2 SIRT-3

BackgroundDelivery of viral vectors as gene therapies to treat neurodegenerative diseases has been hampered by the inability to penetrate the blood brain barrier (BBB) and invasive or non-targeted delivery options prone to inducing immune responses. MR guided focused ultrasound (MR-g-FUS) and microbubbles have demonstrated safe, temporary, targeted BBB permeabilization clinically.MethodsWe developed clinically scalable, microbubble drug conjugates (MDCs) for the viral gene therapy, AAV.SIRT3-myc [adeno-associated virus expressing myc-tagged SIRT3], which has previously been shown to have disease modifying effects in animal models of Parkinson’s disease (PD). The lipid shells of the perfluorocarbon gas MDCs were covalently conjugated to antibodies with binding specificity to AAVs. Following systemic (iv) delivery of AAV.SIRT3-myc MDCs, MR-g-FUS was used to deliver SIRT3-myc to brain regions affected in PD. SIRT3-myc expression was determined post mortem, using immunohistochemistry.ResultsAn in vitro, SH-SY5Y cell culture model was used to show that the localized destruction of MDCs using ultrasound exposures within biological safety limits dissociated AAV2-GFP (green fluorescent protein) from the MDCs in the targeted area while maintaining their transduction capacity. In rats, MR-g-FUS resulted in BBB permeabilization in the striatum and substantia nigra (SNc). SIRT3-myc was expressed in the striatum, but not the SNc.ConclusionThese studies demonstrate that MDCs combined with MR-g-FUS are an effective method for delivery of viral vector gene therapies, such as AAV.SIRT3, to brain regions affected in PD. This technology may prove useful as a disease-modifying strategy in PD and other neurodegenerative disorders.     

DFT-based study of the structural,optoelectronic, mechanical and magnetic properties of Ti3AC2 (A = P,As, Cd) for coating applications

The first-principles approach has been used while employing the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation (PBE-GGA) along with the Hubbard parameter to study the structural, optoelectronic, mechanical and magnetic properties of titanium-based MAX materials Ti₃AC₂ (A = P, As, Cd) for the first time. As there is no band gap found between the valence and conduction bands in the considered materials, these compounds belong to the conductor family of materials. A mechanical analysis carried out at pressures of 0 GPa to 20 GPa and the calculated elastic constants C_ij reveal the stability of these materials. Elastic parameters, i.e., Young''s, shear and bulk moduli, anisotropy factor and Poisson''s ratio, have been investigated in the framework of the Voigt–Reuss–Hill approximation. The calculated values of relative stiffness are found to be greater than ½ for Ti₃PC₂ and Ti₃AsC₂, which indicates that these compounds are closer to typical ceramics, which possess low damage tolerance and fracture toughness. Optical parameters, i.e., dielectric complex function, refractive index, extinction coefficient, absorption coefficient, loss function, conductivity and reflectivity, have also been investigated. These dynamically stable antiferromagnetic materials might have potential applications in advanced electronic and magnetic devices. Their high strength and significant hardness make these materials potential candidates as hard coatings.

The first-principles approach has used the Perdew–Burke–Ernzerhof exchange-correlation functional of generalized gradient approximation along with the Hubbard parameter to study various properties of titanium-based MAX materials Ti₃AC₂ (A = P, As, Cd).     

趋化性细胞因子受体CXCR4在大肠癌的表达及其临床意义

目的:探讨趋化性细胞因子受体CXCR4在大肠癌中的表达及其与预后的关系.方法:收集67例大肠癌患者手术标本,采用免疫组织化学方法检测肿瘤组织中CXCR4蛋白的表达和微血管密度,分析CXCR4的表达水平与临床病理特征和生存的关系.结果:大肠癌组织中CXCR4蛋白表达阳性率为56.7%(38/67),与患者的性别、年龄、肿瘤部位、T分期和病理类型无相关性(P＞0.05),与淋巴结转移、临床分期、微血管密及生存相关.NO,N1和N2期CXCR4的阳性率分别为40.6%,68.2%,76.9%(P＜0.05);Ⅰ Ⅱ期和Ⅲ期CXCR4的阳性率分别为39.4%.73.5%(P＜0.05).低MVD组CXCR4的阳性率显著低于高MVD组(36.4%vs 74.3%,P＜0.01);CXCR4阳性组较CXCR4阴性组有较高的复发/转移率(47.4%vs 24.1%,P＜0.05)和较低的3a无病生存率(32.6%vs 71.3%.P＜0.05).结论:CXCR4可促进大肠癌的侵袭和转移以及血管生成并影响其预后.     

Clinical and scanning electron microscopic features of invasive cervical resorption in a maxillary molar

This case report presents clinical and morphological features of severe invasive cervical resorption (ICR) involving a maxillary first molar. Surface morphology of the ICR defect that extended into enamel was studied using a scanning electron microscope. The topography and morphology of resorbed enamel and pulpal surfaces are described. The pulpal space was characterized by proliferation of fibrovascular tissue invaded by a number of > or = 15-microm-large dentinoclastlike cells. The vertical orientation and hexagonal geometric outlines of enamel rods indicated that the resorptive defect had extended into the outer surface of enamel. Preferential odontoclastic dissolution of interprismatic enamel was noted. Deposits of a cementumlike substance were noticed on enamel surfaces, indicating that resorptive process was coupled with repair. Complete destruction of dentin was associated with no response by the tooth to cold stimulus, supporting the hydrodynamic theory of dentinal sensitivity. The results of this study indicate that in addition to predentin and cementum, the outer surface enamel may be resistant to the resorptive process as well.     

Synthesis and docking studies of N-(5-(alkylthio)-1,3,4-oxadiazol-2-yl)methyl)benzamide analogues as potential alkaline phosphatase inhibitors

A series of N-(5-(alkylthio)-1,3,4-oxadiazol-2-yl)methyl)benzamides 6a–i were synthesized as alkaline phosphatase inhibitors. The intermediate 5-substituted 1,3,4-oxadiazole-2-thione 4 was synthesized starting with hippuric acid. Hippuric acid in the first step was converted into corresponding methyl ester 2 which upon reaction with hydrazine hydrate furnished the formation of hydrazide 3 . The hippuric acid hydrazide was then cyclized into 5-substituted 1,3,4-oxadiazole-2-thione 4 . The intermediate 4 was then reacted with alkyl or aryl halides 5a–5i to afford the title compounds N-(5-(methylthio)-1,3,4-oxadiazol-2-yl)methyl)benzamides 6a–i . The bioassay results showed that compounds 6a–i exhibited good to excellent alkaline phosphatase inhibitory activity. The most potent activity was exhibited by the compound 6i having IC₅₀ value 0.420 μM, whereas IC₅₀ value of standard (KH₂PO₄) was 2.80 μM. Molecular docking studies was performed against alkaline phosphatase enzyme (PDBID 1EW2) to check binding affinity of the synthesized compounds 6a–i against target protein. The docking results showed that three compounds 6c , 6e , and 6i have maximum binding interactions with binding energy values of −8 kcal/mol. The compound 6i displayed the interactions of oxadiazole ring nitrogen with amino acid His265 having a binding distance 2.13 Ǻ. It was concluded from our results that synthesized compounds, especially compound 6i may serve as lead structure to design more potent inhibitors of human alkaline phosphatase.     

Dermatofibrosarcoma Protuberans at the Site of a Central Venous Line

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive cutaneous tumor that usually does not metastasize. Clinically, it may present as a reddish macule to protuberant nodule affecting the trunk and proximal extremities of young and middle-aged adults. Histologically, it is characterized by a monomorphous storiform proliferation of spindle cells, involving the dermis and hypodermis, with a honeycomb pattern of infiltration of the subcutaneous fat. In case of difficulty in diagnosis, immunohistochemical markers (especially CD34) are highly sensitive for DFSP. It is important to remember that the rarity of DFSP, its resemblance to hypertrophied scars and keloids, and its appearance at trauma sites sometimes make the diagnosis of DFSP difficult and delayed. In the literature, DSFP was not described in a child until 1957. Here we report an instance of DFSP at an unusual site in a 9-year-old child, which was the location of a previous central venous line insertion in the left supraclavicular area. A complete excision of the tumor with a wide surgical margin of 3cm of visibly uninvolved tissue was performed, followed by a deltopectoral flap and skin split graft. Postoperatively, the patient's general condition was stable and he was discharged after 5 days to be followed up 3 months later in our clinic.     

Effect of the Source-to-Substrate Distance on Structural,Optoelectronic, and Thermoelectric Properties of Zinc Sulfide Thin Films

Zinc sulfide (ZnS) thin films with variable structural, optical, electrical, and thermoelectric properties were obtained by changing the source-to-substrate (SSD) distance in the physical-vapor-thermal-coating (PVTC) system. The films crystallized into a zinc-blende cubic structure with (111) preferred orientation. The films had a wide 3.54 eV optical band gap. High-quality homogenous thin films were obtained at 60 mm SSD. The sheet resistance and resistivity of the films decreased from 10¹¹ to 10¹⁰ Ω/Sq. and from 10⁶ to 10⁵ Ω-cm, when SSD was increased from 20 mm to 60 mm, respectively. The phase and band gap were also verified by first principles that were in agreement with the experimental results. Thermoelectric characteristics were studied by using the semi-classical Boltzmann transport theory. The high quality, wide band gap, and reduced electrical resistance make ZnS a suitable candidate for the window layer in solar cells.