Selective chemosensors for determination and quantification of various types of molecular target analyte are very important in many fields including chemistry, medicine, and biology. This dissertation describes the efforts of chemosensors for the sensing of metal ions (Hg(II), Fe(III) & Pd(II)) and pharmaceuticals (cephradine & pefloxacin mesylatye). First chapter describes general introduction about chemosensors and nanoparticles. While in the second chapter, synthesis of two new sulfonate and sulfonamide based fluorescent chemosensors, their characterization by EI-MS and 1HNMR and synthesis of gold nanoparticles and silver nanoparticles stabilized Schiff bases have been explained. The synthesized nanoparticles have been characterized by UV-vis spectrophotometric, FTIR and AFM techniques. The average size of synthesized silver nanoparticles were found to be 20-30 nm, and were polydispersed nanoparticles as evidenced by atomic force microscopy. The average size of synthesized gold nanoparticles were found to be 11 nm and were polydispersed. To ascertain the potential for in vivo application, the stability of all synthesized nanoparticles was investigated as a function of pH, temperature and salt concentration. The water suspension of gold nanoparticles were found to be stable for several days at a temperature up to 100 0C, a pH range of 2-13 and salt (NaCl) concentration 5mM-0.01mM. For chemosensing study metals salts and pharmaceuticals were used. The main goal was to achieve sensing in water, which is a prerequisite for application to real blood and tap water samples. The first analyte of choice was heavy metal ion i.e. Hg. The already synthesized probe 218 exhibited marked selectivity for Pb+2 and Hg+2 over 10 other metal ions under physiological buffer condition. Owing to Hg+2 undesirable effects on the environment and the health concerns associated with Hg exposure, this fluorescent probe represents an appealing target and efficient chemosensor for Hg+2. The fluorescence of each solution was measured and the resultant intensity is plotted against concentration of Hg+2 added which shows linear relationship from 10 to 6 μM with a limit of detection of Hg+2 was 0.05 μM and a regression coefficient of 0.907. Another bis-triazol-based fluorescent chemosensor, used as a best sensor for pefloxacin, the chemosensor showed marked quenching among 10 other drugs of interest in aqueous solution, with maximum quenching in intensity at pH 6-8. A novel supramolecular molecular tweezers based on a biphenyl bis-triazole hexahydroquinoline system was used for highly sensitive and selective fluorescent probe for recognizing and detecting cephradine in the presence of other drugs at pH of 7.7. The detection limit was calculated to be 1 μM with a regression coefficient of 0.99. The competivity study, pH sensitivity of the sensor was also studied. The chemosensor allowed the detection of cephradine in tape water too. Among the nanoparticles synthesized, the main attention was paid to the gold nanoparticles chemosensing properties. A pyrazinium thioacetate stabilized gold nanoparticles have been synthesized and were found an excellent sensor for heavy metal Fe(III) and Pd(II) ions in water, without any particular pretreatment. The detection method for Fe(III) by using gold nanoparticles was elegantly applicable over a wide range of pH (2-13) and concentrations (1-100 μM). The regression constant (R2) calculated 0.9813, while the limit of detection (LOD) and the limit of quantification (LOQ) for Fe+3 ions was found to be 4.3 μM and 13.19 μM, respectively. The same pyrazinium thioacetate stabilized gold nanoparticles showed colorimetric change from win-red to grey in the presence of Pd(II). LOD and LOQ for Pd+2 ions were found to be 4.23 μM and 12.83 μM, respectively. Schiff base stabilized gold nanoparticles displayed great selectivity and exhibited best chemosensor properties for pefloxacin in aqueous solution, A linear relationship was almost found when the concentration of pef was between 80 μM to 0.01 μM with a linear regression equation of y=0.0015x + 0.0373 with R2 = 0.9839. LOD was calculated 12.1 μM. The competivity study, pH sensitivity of the sensor was studied. These gold nanoparticles were found to be potent colorimetric sensor and display a very high selectivity for Fe(III), Pd(II) and pefloxacin. The nanoparticle used for the drug sensing allowed the detection of pefloxacin in human serum by simple UV-vis spectroscopic measurements.
ڈاکٹر عبدالستار صدیقی افسوس ہے کہ ہماری علمی بزم کی ایک اہم یادگار ڈاکٹر عبدالستار صدیقی نے گزشتہ مہینے انتقال کیا، وہ اس دور کے مشہور فاضل اور نامور محقق تھے، ان کا موضوع عربی لسانیات تھا، اس کے متعلقات علم الاشتقاق، رسم الحظ حروف و اصوات وغیرہ پر ان کی نظر بڑی دقیق تھی اور اپنی تحریروں میں اس کا بڑا اہتمام رکھتے تھے، ان کی پوری زندگی علمی و تعلیمی خدمات میں گزری، مگر لکھتے کم تھے، انھوں نے غالباً متفرق مضامین کے علاوہ کوئی مستقل تصنیف یادگار نہیں چھوڑی، مگر ان کے یہ مضامین ان کی محققانہ نظر کا ثبوت ہیں، عرصہ ہوا الٰہ آباد ہونیورسٹی کے شعبۂ عربی و فارسی کی صدارت سے ریٹائر ہوئے تھے اور الٰہ آبادی ہی میں سکونت اختیار کرلی تھی، ایک زمانہ میں ہندوستانی اکیڈمی الٰہ آباد کے رکن رکین تھے، یونیورسٹیوں اور دوسری علمی مجالس میں ان کا بڑا وقار تھا، دارالمصنفین کی مجلس انتظامیہ کے بھی رکن تھے، ان کا رہن سہن تو جدید تھا، لیکن شرافت و وضعداری اور شفقت و محبت میں مشرق تہذیب کا نمونہ تھے، ادھر کئی سال سے بالکل معذور ہوگئے تھے، آخر میں ہوش و حواس نے بھی جواب دے دیا تھا، اسی حالت میں گزشتہ جولائی میں انتقال کیا، انتقال کے وقت ۸۷ سال کی عمر تھی، مسلمانوں میں ایسے محقق اب مشکل سے پیدا ہوں گے، اﷲ تعالیٰ ان کی مغفرت فرمائے۔ (شاہ معین الدین ندوی،اگست ۱۹۷۲ء)
Enough of humiliation and what India calls as defaming by the resolutions by OIC on Kashmir, India has dealt with the challenges it had to face to enter into OIC. The tale of challenges faced by India, and the reciprocal attitude of New Delhi is a concrete depiction of international politics based on national interests, and where International organizations voice for human rights but get overpowered by individual member’s national interests. This piece of paper encompasses a show of challenges what India had to face, could overcome them and how creating challenges for its rivals.
Background: A wide variety of sedation techniques are employed to facilitate various invasive diagnostic and therapeutic procedures. Increasingly, propofol is emerging as the preferred sedative agent. Traditionally, it has been administered as intermittent boluses to achieve deep sedation to facilitate gastrointestinal endoscopy. Propofol target controlled infusion can be employed to provide suitably conducive conditions for this purpose. Objective: The primary objective sought to compare the proportion of hypoxia between the study group receiving intermittent boluses of propofol at 0.25mg/kg as needed, and the other receiving target-controlled infusion of propofol at 2.5mcg/ml during upper gastrointestinal endoscopy. The secondary objectives were to compare the occurrence of hypotension, bradycardia, and the time to wake up between the two groups. Primary outcome measure: Decrease in oxygen saturation below 90 percent (SpO2 <90%) Secondary outcome measures: Decrease in systolic blood pressure of more than 20% from baseline; decrease in heart rate to less than 50 beats per minute. Study design: prospective, single centre, randomized controlled trial Study setting: The Aga Khan University Hospital, Nairobi. Sample size: One hundred and seventy-six participants were enrolled; 88 belonging to the intermittent bolus arm and 88, to the target-controlled infusion arm. Study population: Included all ASA I and II patients between the ages of 18 and 65 years scheduled to undergo upper gastrointestinal endoscopy (oesophagogastroduodenoscopy) under sedation. Sedation procedure: One hundred and seventy-six participants were allocated randomly into one of two groups corresponding to the mode of propofol used for sedation (a) Premedication with midazolam 0.05mg/kg added to an initial bolus of propofol 1mg/kg, followed by repeat boluses of 0.25mg/kg as needed (B, n = 88) and (b) Premedication with midazolam 0.05mg/kg added to an initial target effect-site concentration of 4mcg/ml, followed by maintenance target effect-site concentration of 2.5mcg/ml, titrated upward or downward by 0.5mcg/ml from baseline infusion rate as needed (T, n = 88). Oxygenation and haemodynamic parameters were evaluated by determining oxygen saturation, blood pressure and heart rate immediately before administering the sedative and at 2.50, 5.00, 7.50 and 10.00 minutes. Standard care was, in addition to the above, provided. Data collection: A data collection tool was used to record data (refer to appendix V). Patients’ baseline vital signs, including blood pressure, heart rate and oxygen saturation were entered. Any occurrence of oxygen desaturation below 90% in both study groups was also recorded. The sedation starting time, stopping time, waking up time and overall duration of time