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1.
Shaila Lalkuwar Bajoria Virendra Kisan Rathod N. K. Pandey U. Kamachi Mudali R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):271-276
Extraction power of solvent depends upon the physical properties of the system. Tri-n-butyl phosphate (TBP) in dodecane is a versatile solvent used in the nuclear fuel reprocessing like PUREX process. The study of physical properties like density, viscosity, interfacial tension and solubility for TBP–nitric acid–dodecane system will be helpful in carrying out different extraction studies during PUREX process. Thus, physical properties like density, viscosity, interfacial tension and solubility have been measured for TBP–nitric acid–dodecane system using pycnometer, viscometer, pendant drop method and high performance liquid chromatography respectively. It has been observed that density and viscosity increases but interfacial tension and solubility decreases with the concentration of TBP in dodecane–nitric acid system. Physical properties of 30 % TBP–nitric acid–dodecane system have also been studied in detail. All these studies will also be useful in stripping out dissolved TBP from the nuclear waste. 相似文献
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Azucena O Crest J Kotadia S Sullivan W Tao X Reinig M Gavel D Olivier S Kubby J 《Optics letters》2011,36(6):825-827
We report a technique for measuring and correcting the wavefront aberrations introduced by a biological sample using a Shack-Hartmann wavefront sensor, a fluorescent reference source, and a deformable mirror. The reference source and sample fluorescence are at different wavelengths to separate wavefront measurement and sample imaging. The measurement and correction at one wavelength improves the resolving power at a different wavelength, enabling the structure of the sample to be resolved. 相似文献
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Mehwish Nawaz Haji Muhammad Shoaib Khan Naveed Akhtar Talha Jamshed Rubina Qaiser Hina Shoukat Mehrin Farooq 《Photochemistry and photobiology》2019,95(5):1243-1248
Solar radiations trigger the physiological alteration in skin which progress toward photoaging. Sunscreens are known to be effective against the photodamaging effects of sunlight. The purpose of this study was to evaluate the extent to which aging signs caused by real‐life sunlight exposure could be avoided by comparing various parameters between sun‐exposed and sun‐protected skin using noninvasive probes. Female volunteers (n = 11) after getting their consent were provided with marketed sunscreen product to apply onto their skin for 6 months. Measurements were scheduled every 15 days from the baseline reading for 6 months. Cutometer, Mexameter and Corneometer were used for evaluation of facial skin parameters. Clinical evaluations showed the effects of sunlight exposure on different skin parameters by comparing sun‐protected and unprotected skin, where Gross elasticity (R2), Net elasticity (R5), Viscoelasticity (R6) and Biological elasticity (R7) showed insignificant results, while Hydration, Melanin and Erythema showed significant results. Sun‐exposed skin presented 0.72%, 0.66%, 0.77%, 1.39%, 1.99%, 2.01% and 3.15% changes in R2, R5, R6 and R7, melanin, erythema and hydration, respectively, which were potentially prevented by sunscreen application. Premature aging is inhibited by following photoprotective regimen on routine basis, emphasizing the potential benefit of sunscreen against early aging signs. 相似文献
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Mehwish Iftikhar 《Journal of carbohydrate chemistry》2017,36(8-9):295-306
A straightforward synthesis of N-alkylated 1-deoxynojirimycin derivatives modified at the 6-O-position has been described. The key intermediate in the synthesis of target compounds was 2,3,4-tri-O-benzyl-1,5-dideoxy-1,5-imino-D-glucitol, which was prepared from 2,3,4,6-tetra-O-benzyl-1,5-dideoxy-1,5-imino-D-glucitol. Optimal conditions have been established for the synthesis of the key intermediate by varying reaction parameters. Reductive amination and subsequent alkylation of the 6-O-position followed by hydrogenolysis were the main reaction steps, which gave target compounds 6-O-ethyl-N-octyl-1,5-dideoxy-1,5-imino-D-glucitol and 6-O-butyl-N-octyl-1,5-dideoxy-1,5-imino-D-glucitol. This synthetic route is flexible and can be useful for the synthesis of other lipophilic iminosugar derivatives. 相似文献
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Roheena Abdullah Kinza Nisar Aafia Aslam Mehwish Iqtedar Shagufta Naz 《Natural product research》2015,29(11):1006-1011
This study is related to the isolation of fungal strain for xylanase production using agro-industrial residues. Forty fungal strains with xylanolytic potential were isolated by using xylan agar plates and quantitatively screened in solid-state fermentation. Of all the tested isolates, the strain showing highest ability to produce xylanase was assigned the code Aspergillus niger LCBT-14. For the enhanced production of the enzyme, five different fermentation media were evaluated. Out of all media, M4 containing wheat bran gave maximum enzyme production. Effect of different variables including incubation time, temperature, pH, carbon and nitrogen sources has been investigated. The optimum enzyme production was obtained after 72 h at 30°C and pH 4. Glucose as a carbon source while ammonium sulphate and yeast extract as nitrogen sources gave maximum xylanase production (946 U/mL/min). This study was successful in producing xylanase by A. niger LCBT-14 economically by utilising cheap indigenous substrate. 相似文献
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Mehwish Iqtedar Mohammad Nadeem Hira Naeem Roheena Abdullah Shagufta Naz Qurat ul Ain Syed 《Natural product research》2015,29(11):1012-1019
The industrialisation of lignocellulose conversion is impeded by expensive cellulase enzymes required for saccharification in bioethanol production. Current research undertakes cellulase production from pretreated Saccharum spontaneum through Trichoderma viride HN1 under submerged fermentation conditions. Pretreatment of substrate with 2% NaOH resulted in 88% delignification. Maximum cellulase production (2603 ± 16.39 U/mL/min carboxymethyl cellulase and 1393 ± 25.55 U/mL/min FPase) was achieved at 6% substrate at pH 5.0, with 5% inoculum, incubated at 35°C for 120 h of fermentation period. Addition of surfactant, Tween 80 and metal ion Mn+2, significantly enhanced cellulase yield. This study accounts proficient cellulase yield through process optimisation by exploiting cheaper substrate to escalate their commercial endeavour. 相似文献
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Uzma Yasmeen Fazal Haq Mehwish Kiran Arshad Farid Naveed Ullah Tariq Aziz Muhammad Haroon Sahid Mehmood Muhammad Muzammal Shakira Ghazanfar Majid Alhomrani Abdulhakeem S. Alamri Syed Mohammed Basheeruddin Asdaq Saleh A. Alghamdi Irfan Ullah 《Molecules (Basel, Switzerland)》2022,27(18)
In this research, a new biodegradable and eco-friendly adsorbent, starch-grafted polymethyl methacrylate (St-g-PMMA) was synthesized. The St-g-PMMA was synthesized by a free radical polymerization reaction in which methyl methacrylate (MMA) was grafted onto a starch polymer chain. The reaction was performed in water in the presence of a potassium persulfate (KPS) initiator. The structure and different properties of the St-g-PMMA was explored by FT-IR, 1H NMR, TGA, SEM and XRD. After characterization, the St-g-PMMA was used for the removal of MB dye. Different adsorption parameters, such as effect of adsorbent dose, effect of pH, effect of initial concentration of dye solution, effect of contact time and comparative adsorption study were investigated. The St-g-PMMA showed a maximum removal percentage (R%) of 97% towards MB. The other parameters, such as the isothermal and kinetic models, were fitted to the experimental data. The results showed that the Langmuir adsorption and pseudo second order kinetic models were best fitted to experimental data with a regression coefficient of R2 = 0.93 and 0.99, respectively. 相似文献
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Xiaona Rong Nabila Mehwish Xueming Niu Niteng Zhu Bae Hoon Lee 《Macromolecular bioscience》2023,23(3):2200463
Nowadays, hydrogels-based microneedles (MNs) have attracted a great interest owing to their outstanding qualities for biomedical applications. For the fabrication of hydrogels-based microneedles as tissue engineering scaffolds and drug delivery carriers, various biomaterials have been tested. They are required to feature tunable physiochemical properties, biodegradability, biocompatibility, nonimmunogenicity, high drug loading capacity, and sustained drug release. Among biomaterials, human proteins are the most ideal biomaterials for fabrication of hydrogels-based MNs; however, they are mechanically weak and poorly processible. To the best of the knowledge, there are no reports of xeno-free human protein-based MNs so far. Here, human albumin-based hydrogels and microneedles for tissue engineering and drug delivery by using relatively new processible human serum albumin methacryloyl (HSAMA) are engineered. The resultant HSAMA hydrogels display tunable mechanical properties, biodegradability, and good biocompatibility. Moreover, the xeno-free HSAMA microneedles display a sustained drug release profile and significant mechanical strength to penetrate the model skin. In vitro, they also show good biocompatibility and anticancer efficacy. Sustainable processible human albumin-based biomaterials may be employed as a xeno-free platform in vivo for tissue engineering and drug delivery in clinical trials in the future. 相似文献
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Roheena Abdullah Wajeeha Zafar Muhammad Nadeem Mehwish Iqtedar Shagufta Naz Quratulain Syed 《Natural product research》2015,29(12):1133-1138
This study deals with optimisation of cultural conditions for enhanced production of cellulase by Bacillus PC-BC6 and its mutant derivative Bacillus N3. Influence of different variables including incubation time, temperature, inoculum size, pH, nitrogen sources and metal ions has been studied. The optimum conditions for cellulase production were incubation period of 72 h, inoculum size 4% incubation temperature 37°C, pH 7, 0.25% ammonium sulphate, 0.2% peptone as inorganic and organic nitrogen source in case of Bacillus PC-BC6. In case of mutant Bacillus N3, optimal conditions were incubation period of 48 h, incubation temperature 37°C, inoculum size 3%, pH 7, 0.2% ammonium chloride and 0.15% yeast extract. Presence of MnSO4 and CaCl2 enhances the enzyme production by Bacillus PC-BC6 and mutant Bacillus N3, respectively. This study was innovative and successful in producing cellulase economically by using cheap indigenous substrate Saccharum spontaneum. 相似文献