Reactive Oxygen Species, Antioxidants and Signaling in Plants

( Parvaiz Ahmad ),( Maryam Sarwat ),( Satyawati Sharma ) 한국식물학회 2008 Journal of Plant Biology Vol.51 No.3

Thermal and Nonthermal Lattice Gas Models for a Dimer-trimer Surface Catalytic Reaction: A Monte-Carlo Simulation Study

K. Iqbal,Parvaiz A. Khand 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.3

We have studied the kinetics of an irreversible dimer-trimer reaction of the type 2 A_3 + 3 B_2 ! 6 AB by considering the precursor motion of the dimer (B_2) on a square, as well as on a hexagonal surface, by using a Monte Carlo simulation. When the movement of precursors is limited to the first nearest neighborhood, the model gives reactive window widths of the order of 0.22 and 0.29 for the square and the hexagonal lattices, respectively, which are quite large compared to those predicted by the Langmuir-Hinshelwood (LH) model. The phase diagrams resemble qualitatively to those of standard Ziff, Gulari and Barshad (ZGB) model. The width of the reactive window of the precursor model depends upon the mobility of the precursors. The continuous transition disappears when the motion of precursors is extended to the third nearest neighborhood. The diffusion of B atoms to adjacent vacant sites, as well as desorption of the dimer (B_2) from the surface with a certain probability (P), is also considered.

A comprehensive review of phytochemistry, pharmacology and toxicology of the genus Aconitum L.

Sabeena Ali,Rekha Chouhan,Phalisteen Sultan,Qazi Parvaiz Hassan,Sumit G. Gandhi 경희대학교 융합한의과학연구소 2023 Oriental Pharmacy and Experimental Medicine Vol.23 No.2

The genus Aconitum (family—Ranunculaceae) accounts for approximately 400 species worldwide, of which some are considered medicinally very relevant. Many species have been reported to possess significant pharmacological properties and high therapeutic index for curing various diseases. Traditionally, Aconitum species have been used for the treatment of different human ailments, especially, neuronal disorders, pain and inflammation, kidney related disorders, rheumatism, diabetes, hysteria and cardiac depression. These medicinal properties have been attributed to various classes of secondary metabolites found in different Aconitum species. Among them, C19 and C20-diterpenoid alkaloids are the most dynamic group of compounds, comprising of more than 450 alkaloids in various species across the genus. However, further detailed phytochemical investigations of Aconitum species could provide new therapeutic natural products of Aconitum source that could be employed in health and medicine. The present study aims to frame a well structured portfolio to provide contemporary insights of the genus Aconitum. The retrospection of all the available information on Aconitum associated with its various attributes was carried out by searching different electronic databases viz. Elsevier, PubMed, Web of Science, Scifinder, ScienceDirect, ResearchGate, Google Scholar, Bio One, PLOS. The review summarizes the findings on traditional uses, phytochemistry, and pharmacology of various species of the genus. The toxicology and safety of Aconitum species for human consumption as herbal drugs has also been discussed.

Influence of Nanoclays and Nano-TiO2 on the Mechanical and Thermal Properties of Polycarbonate Nanocomposite

Jaya Vani. S,K Nayak,Smita Mohanty,M Rahail Parvaiz 한국고분자학회 2011 Macromolecular Research Vol.19 No.6

Polycarbonate (PC) nanocomposites were prepared using a melt intercalation technique with a series of organically modified clays and nano-TiO_2 (nTiO_2). The effect of the clay and nTiO_2 loading on the morphological,mechanical and thermal behavior of the PC nanocomposites was examined. The modulus enhancement was greater for the nanocomposite formed from PC with clay than the nTiO_2 nanocomposite. These nanocomposites also showed a significant decrease in tensile elongation and ductility with respect to nanoclays incorporation. The nTiO_2 nanocomposites also showed superior mechanical properties to the nanocomposite reinforced with nanoclay. The experimental results were compared with theoretical models. The thermal stability of PC and its nanocomposites were investigated by thermogravimetric analysis (TGA). The glass transition temperature was examined by differential scanning calorimetry (DSC). The incorporation of C30B improved the mechanical and thermal properties up to a 5wt% clay loading due to polar interactions between the PC matrix and the intercalant present in the C30B nanoclay. Wide angle X-ray diffraction (WAXD) showed an increase in the basal spacing of the C30B nanoclay confirming the presence of an intercalated structure. TEM confirmed the intercalation of a C30B clay layers and uniform dispersion of nTiO_2 particles in the PC matrix. The viscoelastic behavior examined by dynamic mechanical analysis (DMA) under a periodic stress revealed the stiffness of the PC nanocomposite in the presence of clay and n-TiO_2.

Spotlight on laparoscopy in the surgical resection of locally advanced rectal cancer: multicenter propensity score match study

Nasir Irfan Ul Islam,Shah Muhammad Fahd,Panteleimonitis Sofoklis,Figueiredo Nuno,Parvaiz Amjad 대한대장항문학회 2022 Annals of Coloproctolgy Vol.38 No.4

Purpose: This study was aimed to assess the feasibility of laparoscopic rectal surgery, comparing quality of surgical specimen, morbidity, and mortality. Methods: Prospectively acquired data from consecutive patients undergoing laparoscopic surgery for rectal cancer, at 2 minimally invasive colorectal units, operated by the same team was included. Locally advanced rectal tumors were identified as T3B or T4 with preoperative magnetic resonance imaging scans. All the patients were operated on by the same team. The 1:1 propensity score matching was performed to create a perfect match in terms of tumor height. Results: Total of 418 laparoscopic resections were performed, out of which 109 patients had locally advanced rectal cancer (LARC) and were propensity score matched with non-LARC (NLARC) patients. Median operation time was higher for the LARC group (270 minutes vs. 250 minutes, P=0.011). However, conversion to open surgery was done in 5 vs. 2 patients (P=0.445), reoperation in 8 vs. 7 (P=0.789), clinical anastomotic leak was found in 3 vs. 2 (P=0.670), and 30-day mortality rates was 2 vs. 1 (P>0.999) between LARC and NLARC, respectively. Readmission rate was higher in the NLARC group (33 patients vs. 19 patients, P=0.026), due to stoma-related issues. There was no statistically significant difference in the R0 resection between the 2 groups (99 patients in LARC vs. 104 patients in NLARC, P=0.284). Conclusion: This study demonstrates that standardized approach to laparoscopy is safe and feasible in LARC. Comparable postoperative short-term clinical and pathological outcomes were seen between LARC and NLARC groups.

Laparoscopy offers better clinical outcomes and long-term survival in patients with right colon cancer: experience from national cancer center

Shah, Muhammad Fahd,Naeem, Awais,Haq, Ihtisham ul,Riaz, Shehryar,Shakeel, Osama,Panteleimonitis, Sofoklis,Khattak, Shahid,Syed, Aamir Ali,Parvaiz, Amjad 대한대장항문학회 2022 Annals of Coloproctolgy Vol.38 No.3

Purpose: Laparoscopic approach to colonic tumor requires skill set and resources to be established as routine standard of care in most centers around the world. It presents particular challenge in country like Pakistan due to economic constrain and lack of teaching and training opportunities available for surgeons to be trained to deliver such service. The aim of this study is to look into changing practice of our institution from conventional approach of open to laparoscopic surgery for right colon cancer. Methods: Consecutive patients between January 2010 to December 2018 who presented to Shaukat Khanum Memorial Cancer Hospital and Research Centre with diagnosis of right colon (cecum, ascending and transverse colon) adenocarcinoma and underwent surgical resections were included in this study. Results: A total of 230 patients with adenocarcinoma of the right colon underwent curative resections during the study period. Of these, 141 patients (61.3%) underwent laparoscopic surgery while open resection was performed in 89 patients (38.7%). Five-year disease-free survival (DFS) of patients with American Joint Committee on Cancer (AJCC) stage III (80.9% vs. 54.8%, P=0.021) was significantly better if these patients underwent laparoscopic surgery while a trend toward better DFS (96.7% vs. 84.1%, P=0.111) was also observed in AJCC stage II patients, although this difference was not significant. Conclusion: This study demonstrates the adoption of a laparoscopic approach for right colon cancer over 10 years. With a standardized approach and using the principle of oncological surgery, we incorporated this in our minimally invasive surgery practice at our institution.

Arbuscular mycorrhizal symbiosis and abiotic stress in plants: A review

Arafat Abdel Hamed Abdel Latef,Abeer Hashem,Saiema Rasool,Elsayed Fathi Abd_Allah,Alqarawi A.A,Dilfuza Egamberdieva,Sumira Jan,Naser A. Anjum,Parvaiz Ahmad 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

Abiotic stresses (such as salinity, drought, cold, heat, mineral deficiency and metals/metalloids) have become major threats to the global agricultural production. These stresses in isolation and/or combination control plant growth, development and productivity by causing physiological disorders, ion toxicity, and hormonal and nutritional imbalances. Some soil microorganisms like arbuscular mycorhizal fungi (AMF) inhabit the rhizosphere and develop a symbiotic relationship with the roots of most plant species. AMF can significantly improve resistance of host plants to varied biotic and abiotic stresses. Taking into account recent literature, this paper: (a) overviews major abiotic stresses and introduces the arbuscular mycorrhizae symbiosis (b) appraises the role and underlying major mechanisms of AMF in plant tolerance to major abiotic stresses including salinity, drought, temperature regimes (cold and heat), nutrient-deficiency, and metal/metalloids; (c) discusses major molecular mechanisms potentially involved in AMF-mediated plant-abiotic stress tolerance; and finally (d) highlights major aspects for future work in the current direction.