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311.
Muhammad Nadeem Waqar Ahmad Adnan Zahir Christophe Hano Bilal Haider Abbasi 《Engineering in Life Science》2019,19(3):168-174
Linum usitatsimum L. (flax) is a perennial herb with magnitude of medicinal and commercial applications. In the present study, we investigated the effects of salicylic acid (SA) on biosynthesis of lignans (secoisolariciresinol diglucoside (SDG) and lariciresinol diglucoside (LDG)) and neolignans (dehydrodiconiferyl alcohol glucoside (DCG) and guaiacylglycerol‐β‐coniferyl alcohol ether glucoside (GGCG)) in cell cultures of flax. Moderate concentration of SA (50 μM) enhanced biomass accumulation (10.98 g/L dry weight (DW)), total phenolic content (37.81 mg/g DW), and antioxidant potential (87.23%) to two‐fold than their respective controls after 72 h of exposure. However, higher levels of total flavonoid content (5.32 mg/g DW) were noted after 48 h of exposure to 50 μM of SA. HPLC analyses revealed that 50 μM SA, significantly enhanced biosynthesis of SDG (7.95 mg/g DW), LDG (7.52 mg/g DW), DCG (54.90 mg/g DW), and GGCG (16.78 mg/g DW), which was almost 2.7, 1.8, 3.88, and 3.98 fold higher than their respective controls after 72 h of exposure time, respectively. These results indicated that moderate concentrations of SA had significant effects on biosynthesis and productivity of lignans and neolignans in cell culture of L. usitatissimum. 相似文献
312.
Iqbal Tahir Khalil Saba Ijaz Mohsin Riaz Khalid Nadeem Khan Muhammad Isa Shakil Muhammad Nabi Azeem Ghulam Javaid Muhammad Abrar Muhammad Afsheen Sumera 《Plasmonics (Norwell, Mass.)》2019,14(3):775-783
Plasmonics - The present work investigates the effect of geometrical parameters of 1D nanograting on surface plasmon resonance (SPR) and plasmonic bandgap (PBG). The use of plasmonic grating device... 相似文献
313.
314.
Altaf Hussain Muhammad Hamid Rashid Raheela Perveen Muhammad Ashraf 《Plant Physiology and Biochemistry》2009,47(3):188-194
We report for the first time kinetic and thermodynamic properties of soluble acid invertase (SAI) of sugarcane (Saccharum officinarum L.) salt sensitive local cultivar CP 77-400 (CP-77). The SAI was purified to apparent homogeneity on FPLC system. The crude enzyme was about 13 fold purified and recovery of SAI was 35%. The invertase was monomeric in nature and its native molecular mass on gel filtration and subunit mass on SDS-PAGE was 28 kDa. SAI was highly acidic having an optimum pH lower than 2. The acidic limb was missing. Proton transfer (donation and receiving) during catalysis was controlled by the basic limb having a pKa of 2.4. Carboxyl groups were involved in proton transfer during catalysis. The kinetic constants for sucrose hydrolysis by SAI were determined to be: km = 55 mg ml?1, kcat = 21 s?1, kcat/km = 0.38, while the thermodynamic parameters were: ΔH* = 52.6 kJ mol?1, ΔG* = 71.2 kJ mol?1, ΔS* = ?57 J mol?1 K?1, ΔG*E–S = 10.8 kJ mol?1 and ΔG*E–T = 2.6 kJ mol?1. The kinetics and thermodynamics of irreversible thermal denaturation at various temperatures 53–63 °C were also determined. The half -life of SAI at 53 and 63 °C was 112 and 10 min, respectively. At 55 °C, surprisingly the half -life increased to twice that at 53 °C. ΔG*, ΔH* and ΔS* of irreversible thermal stability of SAI at 55 °C were 107.7 kJ mol?1, 276.04 kJ mol?1 and 513 J mol?1K?1, respectively. 相似文献
315.
Prion protein (PrP) gene of 308 sheep was genotyped to investigate polymorphisms at scrapie-associated codons 136, 154 and
171 to assess the resistance of nine different Pakistani sheep breeds to natural/typical scrapie. As a result six genotypes
were established on the basis of polymorphic codons 154 and 171. The most scrapie-susceptible codon 136 (A/V) was monomorphic
(A) in all breeds. Wild-type genotype ARQ/ARQ was detected with maximum prevalence ranging from 63.2% in crossbred Pak-karakul
to 100% in native Buchi, Kachi and Thalli breeds. The most frequent of typical scrapie-associated genotypes was ARQ/ARR as
indicated by five of nine breeds. The coding region of PrP gene of 49 animals from the total sampled was also sequenced to
ascertain additional polymorphisms. Polymorphism was found in 13 animals of the six breeds in codons 101(Q/R), 112(M/T), 146(N/S)
and 189(Q/L) and ten genotypes were established on the basis of these polymorphic codons. Only Hissardale possessed five of
the ten genotypes. The most frequent genotype was M112ARQ/T112ARQ detected in Hissardale, Pak-karakul and Awassi, whereas genotypes ARQr231/ARQr231 and ARQR231/ARQr231 (established on the basis of silent polymorphism agg/cgg-R/R) were detected in all breeds. Some animals consisted of three
polymorphisms at different PrP codons that are not common in European breeds. An infrequent double heterozygosity (c/c a/g
g/t) for codon 171 resulting in a genotype R/H was also detected in three animals each one from Kajli, Hissardale and Pak-karakul.
This study concludes that all native sheep breeds are poor in scrapie-resistant PrP genotypes and could contract scrapie if
exposed to prions. 相似文献
316.
Samantha J. Westrop Nadeem A. Qazi Jeffrey Pido-Lopez Mark R. Nelson Brian Gazzard Frances M. Gotch Nesrina Imami 《PloS one》2009,4(5)
Background
HIV-1+ individuals who, without therapy, conserve cellular anti-HIV-1 responses, present with high, stable CD4+ T-cell numbers, and control viral replication, facilitate analysis of atypical viro-immunopathology. In the absence of universal definition, immune function in such HIV controllers remains an indication of non-progression.Methodology/Principal Findings
CD4 T-cell responses to a number of HIV-1 proteins and peptide pools were assessed by IFN-γ ELISpot and lymphoproliferative assays in HIV controllers and chronic progressors. Thymic output was assessed by sjTRECs levels. Follow-up of 41 HIV-1+ individuals originally identified as “Long-term non-progressors” in 1996 according to clinical criteria, and longitudinal analysis of two HIV controllers over 22 years, was also performed. HIV controllers exhibited substantial IFN-γ producing and proliferative HIV-1-specific CD4 T-cell responses to both recombinant proteins and peptide pools of Tat, Rev, Nef, Gag and Env, demonstrating functional processing and presentation. Conversely, HIV-specific T-cell responses were limited to IFN-γ production in chronic progressors. Additionally, thymic output was approximately 19 fold higher in HIV controllers than in age-matched chronic progressors. Follow-up of 41 HIV-1+ patients identified as LTNP in 1996 revealed the transitory characteristics of this status. IFN-γ production and proliferative T-cell function also declines in 2 HIV controllers over 22 years.Conclusions
Although increased thymic output and anti-HIV-1 T-cell responses are observed in HIV controllers compared to chronic progressors, the nature of nonprogressor/controller status appears to be transitory. 相似文献317.
Helicobacter pylori has been shown to degrade two phosphonates, N-phosphonoacetyl-l-aspartate and phosphonoacetate; however, the bacterium does not have any genes homologous to those of the known phosphonate
metabolism pathways suggesting that H. pylori may have a novel phosphonate metabolism pathway. Growth of H. pylori on phosphonates was studied and the catabolism of these compounds was measured employing 1H-nuclear magnetic resonance spectroscopy. The specificity of the catabolic enzymes was elucidated by assaying the degradation
of several phosphonates and through substrate competition studies. H. pylori was able to utilise phenylphosphonate as a sole source of phosphate for growth. Three strains of H. pylori showed sigmoidal enzyme kinetics of phenylphosphonate catabolism. Allosteric kinetics were removed when lysates were fractionated
into cytosolic and membrane fractions. Catabolic rates increased with the addition of DTT, Mg2+ and phosphate and decreased with the addition of EDTA. The physiological properties of H. pylori phosphonate metabolism were characterised and the presence of at least two novel phosphonate catabolism pathways that do
not require phosphate starvation growth conditions for activity has been established. 相似文献
318.
Ahmad N Hamayun M Khan SA Khan AL Lee IJ Shin DH 《Journal of microbiology and biotechnology》2010,20(12):1744-1749
The role of endophytic fungi in plant growth and development is well documented. However, endophytic fungi with growth promotion capacity have never been isolated from weeds previously. In the current study, we isolated 8 fungal endophytes from the roots of Monochoria vaginalis, a serious weed of rice paddy in Korea. These isolates were screened on Waito-C, in order to identify plant growth promoting metabolites. Two fungal isolates (M5.A & M1.5) significantly promoted the plant height and shoot length of Waito-C during preliminary screening experiments. The culture filtrates (CFs) of M5.A and M1.5 also promoted the shoot length of Echinocloa crusgalli. Gibberellins (GAs) analysis of the CFs of M5.A and M1.5 showed that these endophytic fungi secrete higher quantities of GAs as compared with wild-type G. fujikuroi KCCM12329. The CF of M5.A contained bioactive GAs (GA3, 2.8 ng/ml; GA4, 2.6 ng/ml, and GA7, 6.68 ng/ml) in conjunction with physiologically inactive GA9 (1.61 ng/ml) and GA24 (0.18 ng/ml). The CF of M1.5 contained physiologically active GAs (GA3, 1.64 ng/ml; GA4, 1.37 ng/ml and GA7, 6.29 ng/ml) in conjunction with physiologically inactive GA9 (3.44 ng/ml), GA12 (0.3 ng/ml), and GA24 (0.59 ng/ml). M5.A and M1.5 were identified as new strains of Penicillium sp. and Aspergillus sp., respectively, based on their 18S rDNA sequence homology and phylogenetic analysis. 相似文献
319.
Munira Borhany Zaen Pahore Zeeshan ul Qadr Muhammad Rehan Arshi Naz Asif Khan Saqib Ansari Tasneem Farzana Muhammad Nadeem Syed Amir Raza Tahir Shamsi 《Orphanet journal of rare diseases》2010,5(1):1-7
Objective
To determine the frequency and clinical features of bleeding disorders in the tribe as a result of consanguineous marriages.Design
Cross Sectional StudyIntroduction
Countries in which consanguinity is a normal practice, these rare autosomal recessive disorders run in close families and tribes. Here we describe a family, living in village Ali Murad Chandio, District Badin, labeled as haemophilia.Patients & Methods
Our team visited the village & developed the pedigree of the whole extended family, up to seven generations. Performa was filled by incorporating patients, family history of bleeding, signs & symptoms, and bleeding from any site. From them 144 individuals were screened with CBC, bleeding time, platelet aggregation studies & RiCoF. While for PT, APTT, VWF assay and Factor VIII assay, samples were kept frozen at -70 degrees C until tested.Results
The family tree of the seven generations comprises of 533 individuals, 63 subjects died over a period of 20 years and 470 were alive. Out of all those 144 subjects were selected on the basis of the bleeding history. Among them 98(68.1%) were diagnosed to have a bleeding disorder; 44.9% patients were male and 55.1% patients were female. Median age of all the patients was 20.81, range (4 months- 80 yrs). The results of bleeding have shown that majority had gum bleeding, epistaxis and menorrhagia. Most common bleeding disorder was Von Willebrand disease and Platelet functional disorders.Conclusion
Consanguineous marriages keep all the beneficial and adversely affecting recessive genes within the family; in homozygous states. These genes express themselves and result in life threatening diseases. Awareness, education & genetic counseling will be needed to prevent the spread of such common occurrence of these bleeding disorders in the community. 相似文献320.
In this investigation, peristaltic flow of Walter’s B fluid in a uniform inclined tube is discussed. The formulation of the
problem is made in a cylindrical coordinate system. The analytical solutions have been calculated by using a regular perturbation
method by taking δ as the perturbation parameter. The expressions for pressure rise and friction forces were calculated using numerical integration.
The graphical results are presented to discuss the various physical quantities of the Walter’s B fluid parameter α, amplitude ratio φ, angle of inclination β and wave length δ. 相似文献