An Analytical and Experimental Study of Clearance and Bearing-Bypass Load Effects in Composite Bolted Joints

A combined analytical and experimental study is conducted to determine the effects of clearance and bearing-bypass loading for mechanically fastened joints in composites. A simple method of analysis is developed to account for the nonlinear effects of bolt-hole clearance. The nonlinear load-contact variations for clearance-fit fasteners are also measured using specially instrumented fasteners. For a quasi-isotropic graphite/epoxy laminate, results show that the contact arc as well as the peak stresses around the hole and their locations are strongly influenced by the clearance. After a slight initial nonlinearity, the peak stresses vary linearly with applied load. The typical clearance levels are shown to have only a minor influence on the overall joint stiffness. Quasi-isotropic graphite/epoxy laminates (T300/5208) are tested under combined bearing and bypass loading to study failure modes and strengths. Radiographs are made after damage onset and after ultimate load to examine the failure modes. Also the laminate stresses near the bolt-hole are calculated for each test condition, and then used with appropriate failure criteria to analyze the test data. The tension data show a linear interaction for combined bearing and bypass loading with damage developing in the net-tension mode and growing to failure in the same mode. Failure modes are more complex in compression. The compression bearing-bypass strengths for damage-onset show an unexpected interaction involving the bearing mode. Compressive bypass loads reduce the bearing strength by decreasing the bolt-hole contact arc and thus increasing the severity of the bearing loads. Bearing damage-onset, for compressive bearing-bypass loads, causes a weakening of the offset-section leading to ultimate failure in the offset compreson-bearing mode. Damage-onset is predicted reasonably well using the peak stresses at the hole. Strength predictions indicate that damage corresponding to ultimate strength is governed by the maximum stress near the hole. This investigation will help improve the basic understanding of composite bolted joints and lead to better structural design procedures

Geographical variation in Chemo profile, Genetic profile and In-vitro Anticancer activity of Chitraka (Plumbago zeylanica Linn.) collected from Himalayas and Western Ghats

Therapeutic actions of medicinal plants are due to the chemical components present in them. These chemical constituents often vary with change in geographical and climatic conditions. Climate, altitude, and temperature play an important role to make a herb therapeutically potent. Ancient Ayurvedic physicians mentioned that medicinal plants which grow in Himalayan region are more potent as compared to the plants growing in other regions. A modest study was therefore undertaken to compare the in vitro anticancer activity of Plumbago zeylanica Linn. collected from Himalayan region and Western Ghats with respect to their chemo profile and genetic patterns. Variation in physio-chemical, phyto-chemical, the genetic profiles were observed in plants collected from these two regions and corresponding variation was also seen in their anticancer activities

Intramedullary nailing versus plating in shaft humerus fractures: a prospective randomized study

Introduction- The two most commonly used modalities of internal fixation in fracture shaft of humerus are Plate osteosynthesis and Intramedullary nailing. The present study aims to analyze and compare both the techniques in terms of functional and radiological outcome. Material and Methods- 43 patients with diaphyseal fracture humerus were treated with Intramedullary nailing and plating between March 2015 and March 2016. The inclusion criteria were patients with closed diaphyseal fracture humerus. Compound fractures, pathological fractures, Non-union, mal-union fractures were excluded from the study. Results- 22 (51.2%) cases were operated using the antegrade nailing technique whereas dynamic compression plating was done in 21 (48.8%) cases. The mean age was 42±4.2 years. Road traffic accident was the most common mechanism of injury with 29 (67.5%) cases. 12-A2 type of fracture pattern were most common involving 23 (53.5%) cases. The mean surgical time was 68 mins in cases where nailing was done and 115 mins in cases with plating (P<0.001). Radiological union was seen at 13±4.8 weeks and 15±3.9 weeks in the nailing and plating group respectively. There were 2 (9.09%) cases in the nailing group and 1 (4.7%) case in the plating group which had delayed union. 3 (13.6%) cases in the nailing group had post-operative shoulder stiffness. The mean ASES score at the end of one year was 31.3 in nailing andBackground: The two most commonly used modalities of internal fixation in fracture shaft of humerus are plate osteosynthesis and intramedullary nailing. The present study aims to analyze and compare both the techniques in terms of functional and radiological outcome.Methods: 43 patients with diaphyseal fracture humerus were treated with Intramedullary nailing and plating between March 2015 and March 2016. The inclusion criteria were patients with closed diaphyseal fracture humerus. Compound fractures, pathological fractures, non-union, mal-union fractures were excluded from the study.Results: 22 (51.2%) cases were operated using the antegrade nailing technique whereas dynamic compression plating was done in 21 (48.8%) cases. The mean age was 42±4.2 years. Road traffic accident was the most common mechanism of injury with 29 (67.5%) cases. 12 A2 type of fracture pattern were most common involving 23 (53.5%) cases. The mean surgical time was 68 minutes in cases where nailing was done and 115 minutes in cases with plating (P <0.001). Radiological union was seen at 13±4.8 weeks and 15±3.9 weeks in the nailing and plating group respectively. There were 2 (9.09%) cases in the nailing group and 1 (4.7%) case in the plating group which had delayed union. 3 (13.6%) cases in the nailing group had post-operative shoulder stiffness. The mean ASES score at the end of one year was 31.3 in nailing and 29.6 in plating group (P =0.327). There were 37 (86.5%) cases with excellent to good results. Conclusions: Nailing and plating have equal functional outcomes in cases with shaft humerus fracture.29.6 in plating group (P=0.327). There were 37 (86.5%) cases with excellent to good results. Conclusion- Nailing and plating have equal functional outcomes in cases with shaft humerus fracture

Impacts of center and clinical factors in antihypertensive medication use after kidney transplantation

Hypertension guidelines recommend calcium channel blockers (CCBs), thiazide diuretics, and angiotensin‐converting‐enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs) as first‐line agents to treat hypertension. Hypertension is common among kidney transplant (KTx) recipients, but data are limited regarding patterns of antihypertensive medication (AHM) use in this population. We examined a novel database that links national registry data for adult KTx recipients (age > 18 years) with AHM fill records from a pharmaceutical claims warehouse (2007‐2016) to describe use and correlates of AHM use during months 7‐12 post‐transplant. For patients filling AHMs, individual agents used included: dihydropyridine (DHP) CCBs, 55.6%; beta‐blockers (BBs), 52.8%; diuretics, 30.0%; ACEi/ARBs, 21.1%; non‐DHP CCBs, 3.0%; and others, 20.1%. Both BB and ACEi/ARB use were significantly lower in the time period following the 2014 Eighth Joint National Committee (JNC‐8) guidelines (2014‐2016), compared with an earlier period (2007‐2013). The median odds ratios generated from case‐factor adjusted models supported variation in use of ACEi/ARBs (1.51) and BBs (1.55) across transplant centers. Contrary to hypertension guidelines for the general population, KTx recipients are prescribed relatively more BBs and fewer ACEi/ARBs. The clinical impact of this AHM prescribing pattern warrants further study.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154651/1/ctr13803.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154651/2/ctr13803_am.pd

Outcome implications of benzodiazepine and opioid co- prescription in kidney transplant recipients

The outcomes of benzodiazepine and opioid co- prescription are not well- defined in transplant populations. We examined linked national transplant registry and pharmaceutical records to characterize benzodiazepine and opioid use in the years before and after transplant in large US cohort of kidney transplant recipients (2007- 2016; N = 98 620), and associations (adjusted hazard ratio, LCLaHRUCL) with death and graft failure. Among the cohort, 15.6% filled benzodiazepine prescriptions in the year before transplant, and 14.0% filled benzodiazepine prescriptions in the year after transplant (short- acting, 9.5%; long- acting, 3.3%; both 1.1%). Use of short- acting benzodiazepines in the year before transplant was associated with a 22% increased risk of death in the year after transplant (aHR, 1.081.221.38), while use of all classes in the year after transplant was associated with increased risk of death from >1 to 5 years (aHR: short- acting 1.291.391.48; long- acting 1.121.251.40; both 1.461.742.07). Recipients who used benzodiazepines were also more likely to fill opioid prescriptions. Recipients who filled both classes of benzodiazepine and the highest level of opioids had a 2.9- fold increased risk of death compared to recipients who did not use either. Co- prescription of benzodiazepines and opioids in kidney transplant recipients is associated with increased mortality. Ongoing research is needed to understand mechanisms of risk relationships.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162821/2/ctr14005.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162821/1/ctr14005_am.pd

Center practice drives variation in choice of US kidney transplant induction therapy: a retrospective analysis of contemporary practice

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141776/1/tri13079_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141776/2/tri13079.pd

Choice Models and Customer Relationship Management

Customer relationship management (CRM) typically involves tracking individual customer behavior over time, and using this knowledge to configure solutions precisely tailored to the customers' and vendors' needs. In the context of choice, this implies designing longitudinal models of choice over the breadth of the firm's products and using them prescriptively to increase the revenues from customers over their lifecycle. Several factors have recently contributed to the rise in the use of CRM in the marketplacePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47023/1/11002_2005_Article_5892.pd