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匹配条件: “R. John Mathew” ,找到相关结果约252086条。
R. John Mathew
Journal of Global Research in Mathematical Archives , 2013,
Abstract: In this paper we develop and analyse an inventory model for deteriorating items with Weibull rate of decay having finite rate of replenishment and selling price dependent demand. Using the differential equations, the instantaneous state of inventory at time ‘t’, the amount of deteriration etc. are derived. With suitable cost considerations the total cost function and profit rate function are also obtained by maximizing the profit rate function, the optimal ordering and pricing policies of the model are derived. The sensitivity of the model with respect to the parameters is discussed through numerical illustration. It is observed that the deteriorating parameters have a tremendous influence on the optimal selling price and ordering quantity. Keywords: Perishability, Instantaneous rate of deterioration, Total cost function, Profit rate function, the optimal ordering and pricing policies.
Acid Dissociation Constants and Related Thermodynamic Functions of Protonated 2,2-Bis(Hydroxymethyl)-2,2’,2”- Nitrilotriethanol (BIS-TRIS) from (278.15 to 328.15) K  [PDF]
Rabindra N. Roy, Lakshmi N. Roy, Katherine E. Hundley, John J. Dinga, Mathew R. Medcalf, Lucas S. Tebbe, Ryan R. Parmar, Jaime A. Veliz
Journal of Biophysical Chemistry (JBPC) , 2014, DOI: 10.4236/jbpc.2014.53013
Thermodynamic dissociation constants pKa of 2,2-bis(hydroxymethyl)-2,2’,2”-nitrilotriethanol have been determined at 12 temperatures from (278.15 to 328.15) K including the body temperature 310.15 K by the electromotive-force measurements (emf) of hydrogen-silver chloride cells without liquid junction of the type: Pt(s), H2(g), 101.325 kPa|BIS-TRIS (m) + BIS-TRIS·HCl (m)| AgCl(s), Ag(s), where m denotes molality. The pKa values for the dissociation process of BIS-TRIS·H++ H2O = H3O+ + BIS-TRIS given as a function of T in Kelvin (K) by the equation pKa = 921.66 (K/T) + 14.0007-1.86197 ln(T/K). At 298.15 and 310.15 K, the values of pKa for BIS-TRIS were found to be 6.4828 ± 0.0005 and 6.2906 ± 0.0006 respectively. Thus buffer solutions composed of BIS-TRIS and its hydrochloride would be useful as secondary pH buffer standards and for control of acidity in the pH range 6 to 8. At 298.15 K the thermodynamic functions \"\"G°, \"\"H°, \"\"S° and \"\"Cp° for the dissociation process of BIS-TRIS·H+ are \"\"G°=37,005 J·mol-1, \"\"H° = 28,273 J·mol-1, \"\"S°= 29.3 J·K-1·mol-1 and \"\"Cp° = 36 J·K-1·mol-1. These results are compared with the dissociation of protonated bases structurally related to BIS-TRIS·H+.
Dissociation Constant of N-(2-Acetamido)-Iminodiacetic Acid Monosodium (ADA) from (278.15 to 328.15) K  [PDF]
Rabindra N. Roy, Lakshmi N. Roy, John J. Dinga, Mathew R. Medcalf, Katherine E. Hundley, Eric B. Hines, Clark B. Summers, Lucas S. Tebbe, Jamie Veliz
Open Journal of Physical Chemistry (OJPC) , 2014, DOI: 10.4236/ojpc.2014.42011

The acidic dissociation constant of N-(2-acetamido)-iminodiacetic acid monosodium (ADA) has been determined at 12 temperatures from 278.15 to 328.15 K by electromotive-force (emf) measurements of hydrogen-silver chloride cells without liquid junction. At 298.15 K, the value of the dissociation constant (pK2) is 6.8416 ± 0.0004. In response to the need for new physiological pH standards, buffer solutions of NaADA and its disodium salt, Na2ADA would be useful for pH control in the biological region of pH 6.5 to 7.5. The pK2 values over the experimental temperature range are given as a function of the thermodynamic temperature (T) by the equation pK2 = 2943.784/T - 47.05762 + 7.72703 ln T. At 298.15 K, standard thermodynamic quantities for the dissociation process have been derived from the temperature coefficients; ΔH° = 12,252 J·mol-1, ΔS° = -89.9 J·K-1

Early peri-operative hyperglycaemia and renal allograft rejection in patients without diabetes
Merlin C Thomas, John Moran, Timothy H Mathew, Graeme R Russ, M Mohan Rao
BMC Nephrology , 2000, DOI: 10.1186/1471-2369-1-1
Abstract: Hyperglycaemia (>8.0 mmol/L) occurs in over 73% of non-diabetic patients following surgery. Glycaemic control immediately following renal transplantation independently predicted acute rejection (Odds ratio=1.08). 42% of patients with a glucose < 8.0 mmol/L following surgery developed rejection compared to 71% of patients who had a serum glucose above this level. Hyperglycaemia was not associated with any delay of graft function.Hyperglycaemia is associated with an increased risk for allograft rejection. This is consistent with similar findings in patients with diabetes. We hypothesise a causal link concordant with epidemiological and in vitro evidence and propose further clinical research.Hyperglycaemia is common following renal transplantation [1]. Aside from patients with diabetes, many dialysis patients have impaired glucose tolerance [2] and much of the standard post-transplant management is diabetogenic. Recent data has demonstrated that patients with diabetes are at increased risk for allograft rejection [3]. We have recently described how glycaemic control correlates with allograft rejection in patients with diabetes, raising the possibility of a causal association between peri-operative hyperglycaemia and allograft rejection [4]. Transplantation is a unique situation where naive tissue may be suddenly subjected to a hostile hyperglycaemic environment. Acute rejection is thought to be initiated in the early postoperative period by antigen presentation, possibly in response to allograft inflammation and injury. Acute hyperglycaemia is known to enhance ischaemic injury [5], antigen presentation [6], apoptosis [7], and augment the inflammatory response [8]. We hypothesise that exposure of allograft tissue to hyperglycaemia could influence the risk for rejection, not only in diabetes, but in any patient with an elevated glucose. This study investigates the relationship of peri-operative hyperglycaemia to acute rejection in patients without diabetes.A retrospectiv
Evaluation of real-time PCR endogenous control genes for analysis of gene expression in bovine endometrium
Caroline G Walker, Susanne Meier, Murray D Mitchell, John R Roche, Mathew Littlejohn
BMC Molecular Biology , 2009, DOI: 10.1186/1471-2199-10-100
Abstract: The expression profiles of five commonly used endogenous control genes (GAPDH, PPIA, RPS9, RPS15A, and UXT) and 10 experimentally derived candidate endogenous control genes (SUZ12, C2ORF29, ZNF131, ACTR1A, HDAC1, SLC30A6, CNOT7, DNAJC17, BBS2, and RANBP10) were analysed across 44 samples to determine the most stably expressed gene. Gene stability was assessed using the statistical algorithms GeNorm and Normfinder. All genes presented with low overall variability (0.87 to 1.48% CV of Cq). However, when used to normalise a differentially expressed gene (oxytocin receptor - OXTR) in the samples, the reported relative gene expression levels were significantly affected by the control gene chosen. Based on the results of this analysis, SUZ12 is proposed as the most appropriate control gene for use in bovine endometrium during early pregnancy or the oestrus cycle.This study establishes the suitability of novel endogenous control genes for comparing expression levels in endometrial tissues of pregnant and cycling bovines, and demonstrates the utility of microarray analysis as a method for identifying endogenous control gene candidates.Quantitative real-time reverse transcription PCR (RT-PCR) is an extremely sensitive technique that allows the precise measurement of gene expression across more than seven orders of magnitude[1,2]. RT-PCR is often considered the gold standard for quantifying gene expression, and is commonly used to validate techniques with greater throughput but less overall sensitivity, such as microarray analysis [3-5]. RT-PCR relies on the use of fluorescent dyes to quantify transcript amplification, with the amplification cycle number at which these dyes/transcripts are detected (above background) giving an indication as to the relative abundance of the target molecules. The sensitivity of RT-PCR makes it a powerful tool for gene expression measurement, especially when sample quantities are limited or a transcript is expressed at a low level. However, this
Modulation of the maternal immune system by the pre-implantation embryo
Caroline G Walker, Susanne Meier, Mathew D Littlejohn, Klaus Lehnert, John R Roche, Murray D Mitchell
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-474
Abstract: Microarray analyses revealed 1,839 and 1,189 differentially expressed transcripts between pregnant and cyclic animals (with ≥ 1.5 fold change in expression; P-value < 0.05, MTC Benjamini-Hochberg) in caruncular and intercaruncular endometrium respectively. Gene ontology and biological pathway analysis of differentially expressed genes revealed enrichment for genes involved in interferon signalling and modulation of the immune response in pregnant animals.The maternal immune system actively surveys the uterine environment during early pregnancy. The embryo modulates this response inducing the expression of endometrial molecules that suppress the immune response and promote maternal tolerance to the embryo. During this period of local immune suppression, genes of the innate immune response (in particular, antimicrobial genes) may function to protect the uterus against infection.Over the past three decades, there has been a coincidental decline in fertility associated with genetic selection for increased milk production. It is estimated that approximately 50% of the potential profitability from genetic selection for milk production is lost due to a reduction in fertility [1].The fertilisation rate for lactating dairy cattle is around 90% and does not differ between low-moderate and high-producing animals when managed under pastoral conditions[2]. However, the calving rate in lower producing animals is approximately 55%, whereas for high-producing animals, this rate is approximately 35%[2]. Pregnancy losses are thought to occur primarily during the pregnancy recognition/pre-implantation period [2], making studies of endometrial gene expression critical to further understanding of pregnancy establishment, recognition and maintenance within the bovine reproductive cycle.Successful pregnancy in mammals requires both a viable embryo and a receptive endometrium. Synchronous signalling between the endometrium and embryo during the pre-implantation period is critical for norma
Melaena with Peutz-Jeghers syndrome: a case report
Sayantan Bhattacharya, Sunondo R Mahapatra, Ramlal Nangalia, Amitabh Palit, John R Morrissey, Ernie Ruban, Vijay Jadhav, George Mathew
Journal of Medical Case Reports , 2010, DOI: 10.1186/1752-1947-4-44
Abstract: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed.Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences.Peutz-Jeghers syndrome (PJS) is a rare familial disorder, with an incidence of 1 in 12-30,000 live births [1]. It is an autosomal dominant condition with incomplete penetrance [2]. Nonsense, frameshift and missense mutations inactivating the LKB1 gene on chromosome 19p13.3 have been implicated as the underlying abnormality [3].PJS presents with characteristic flat, pigmented, freckle-like cutaneous lesions mainly on the lower lip, perioral area, buccal mucosa, periorbital area and eyelids. The syndrome is also associated with gastrointestinal and extragastrointestinal hamartomatous polyps. The typical pathological feature of Peutz-Jegher polyp (PJP) is a smooth muscle core arising from the muscularis mucosae and ramifying into the substance of the polyp like the branches of a tree.The World Health Organisation (WHO) clinico-pathological criteria for diagnosing this rare disorder are [4]:1. Three or more polyps, which show histological features consistent with PJS.2. A family history of PJS with any number of PJPs.3. A family history of PJS with characteristic mucocutaneous pigmentation.4. Characteristic mucocutaneous pigmentation with any number of PJPs.Individuals with this condition carry a very hig
Detection and measurement of oral malodour in periodontitis patients
John Mathew,Vandana K
Indian Journal of Dental Research , 2006,
Abstract: BACKGROUND &OBJECTIVES : Malodour has been correlated with the concentration of volatile sulphur compounds produced in the oral cavity by metabolic activity of bacteria colonizing the periodontal sites and the dorsum of the tongue. The aim of this study was to detect malodour in mouth air organoleptically and using a portable sulphide monitor and to correlate it with the clinical parameters, halitosis linked toxins and BANA, using tongue and subgingival plaque samples. The halitosis grading is also correlated with the microbial colonies of the subgingival plaque sample. METHODS : 20 patients with chronic periodontitis with 5-7 mm pocket depth, radiographic evidence of bone loss and presence of oral malodour participated in this study. Assessment of mouth air was done organoleptically and by using a portable sulphide monitor. The clinical parameter, plaque index (PI), gingival index (GI), gingival bleeding index (BI), were obtained from all the areas. Samples for BANA and to detect halitosis linked toxins were taken from the dorsal surface of the tongue and periodontal pockets ranging 5-7 mm. Halitosis related microbial colonies were identified using anaerobic culturing from the subgingival plaque. RESULTS : The scores of PI, GI, BI and sample that tested positive for halitosis linked toxins and with the halitosis grading were not significant. The presence of tongue coating and the halitosis grading and toxin levels were significant. BANA has shown to be non contributory due to technical problems. Anaerobic culture has shown to identify Streptococcus, Bacteroides, Fusobacterium, Porphyromonas and Prevotella colonies. INTERPRETATION &CONCLUSION : The results confirmed that there was no correlation between the clinical parameters, halitosis linked toxins and halitosis grading. The microbial colonies have shown to correlate with the presence of oral malodour.
Insulin prescription errors
Mathew John,Senthil V
Journal of Postgraduate Medicine , 2005,
Postcranial pneumaticity in dinosaurs and the origin of the avian lung
Mathew John Wedel
Quantitative Biology , 2013,
Abstract: In birds, diverticula of the lungs and air sacs pneumatize specific regions of the postcranial skeleton. Relationships among pulmonary components and skeletal regions they pneumatize allow inferences about pulmonary anatomy in non-avian dinosaurs. Fossae, foramina and chambers in the postcranial skeletons of pterosaurs and saurischian dinosaurs are diagnostic for pneumaticity. In basal saurischians only the cervical skeleton is pneumatized, by cervical air sacs. In more derived saurischians pneumatization of posterior dorsal, sacral, and caudal vertebrae indicates abdominal air sacs. Abdominal air sacs in sauropods are also indicated by a pneumatic hiatus (a gap in vertebral pneumatization) in Haplocanthosaurus. Minimally, saurischians had dorsally attached diverticular lungs plus anterior and posterior air sacs, and all the pulmonary prerequisites for flow-through lung ventilation like that of birds. Pneumaticity reduced skeletal mass in saurischians. I propose the Air Space Proportion (ASP) as a measure of proportional volume of air in pneumatic bones. The mean ASP of a sample of sauropod and theropod vertebrae is 0.61, so on average, air occupied more than half the volume of these vertebrae. In Diplodocus, pneumatization lightened the living animal by 7-10 percent, and that does not include extraskeletal diverticula, air sacs, lungs, or trachea. If all these air reservoirs included, the specific gravity of Diplodocus is 0.80, higher than published values for birds but lower than those for squamates and crocodilians. Pneumatization of cervical vertebrae facilitated evolution of long necks in sauropods. Necks longer than nine meters evolved at least four times, in mamenchisaurs, diplodocids, brachiosaurids, and titanosaurs. Increases in the number of cervical vertebrae, their proportional lengths, and their internal complexity occurred in parallel in most of these lineages.

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