Physicochemical and tribophysical properties of trioctylalkylammonium bis(salicylato)borate (N888n-BScB) ionic liquids: effect of alkyl chain length.

The alkyl chain length of trioctylalkylammonium bis(salicylato)borates (N888n-BScB; n = 6, 8, 10 and 12) was varied to prepare a series of room-temperature ionic liquids, and then their viscosity and rheological properties were investigated. Besides the omnipresent Coulombic interactions, other interactive forces such as van der Waals interactions, hydrogen bonding, inductive forces, dipole-dipole interactions, etc., collectively determine the physicochemical properties of N888n-BScB ionic liquids. The van der Waals interactions and structural geometry of the ammonium cation (N888n) primarily organized the packing orientation of N888n-BScB ionic liquids and controlled their viscosity and rheological properties as a function of the alkyl chain length. The symmetric cation (N8888) increased the viscosity owing to closer packing driven by van der Waals interactions. The N888n-BScB ionic liquids exhibited non-Newtonian shear thinning behaviour. Furthermore, the decrease in viscosity at higher shear rates indicated that interactive forces in the N888n-BScB ionic liquids were disrupted. These ionic liquids, as lubricants, exhibited significantly lower friction (40-50%) and wear (45-69%) in comparison to PEG 300 synthetic lubricating oil. The degrees of reduction in friction and wear were largely influenced by the chain length of the alkyl group. The N888n-BScB ionic liquids with longer alkyl chains were strongly adsorbed on sliding surfaces and provided better lubrication properties than those with shorter alkyl chains. As a result, the coefficients of friction and wear were decreased by increasing the chain length in N888n-BScB ionic liquids. The tribologically induced adsorption of the BScB anion on metal surfaces, electrostatic interactions between ions, the compact and rigid structure of the BScB anion and van der Waals interactions provided by longer alkyl chains in the N888n cation collectively formed a tribochemical thin film of low shear strength, which resulted in a reduction in friction and the avoidance of direct contact between the aluminium and steel tribopair.

Indian Science Culture Needs a Paradigm Shift.

There is a general impression in the scientific community in our country that the way science is taught, leant and the work culture of research and management of academic and research institutions is not conducive to cutting edge research, innovation and making world leaders. Mentoring continues to be poor with some exceptions. Very often, senior scientists with long innings in science teaching and research express anguish at the status quo in spite of a number of policy documents and recommendations for change. Indian science culture (teaching, research as well as administration) is a matter of prime concern and the issues cannot be pushed under the carpet if we desire a qualitative change. Most of the institutions of higher learning churn out graduates and post graduates who are largely unemployable. There are concerns on the number of Ph.Ds and not on the quality of Ph.D. One major consequence of the weak post graduates and Ph.Ds is the non-availability of competent faculty. Weakness and lack of interest in science learning starts from school. Learning continues to be by rote which is the prime reason for our low global rank in science and mathematics competence. Teaching and research apart there are umpteen other issues in over all culture of institutions and universities engaged in science teaching and research. Few oases of excellence are exceptions in the vast pool of mediocrity. Some points which need prime attention are: adoption of a tenure track system on the pattern of US institutions; feedback on and evaluation of teaching and mentoring; bottom up approach for candid feedback on issues which require long term solutions for efficiency and sound deliverables, cultivating the culture of working in front line areas, full transparency in working and an all out exit from culture of feudalism. This transformation needs commitment on the part of the politicians who man the respective departments of science education, research and human resource development. I am sure such a cultural change and paradigm shift from the status quo does not need extra funds and can be surely ushered in without money.

Alkylamine-functionalized hexagonal boron nitride nanoplatelets as a novel material for the reduction of friction and wear.

Hexagonal boron nitride nanoplatelets (h-BNNPs), which are structurally analogous to graphene, were prepared via the ultrasound-assisted exfoliation of h-BN powder using N-methyl pyrrolidone as the solvent. The alkylamines with variable alkyl chains and electron-rich nitrogen atoms were grafted onto the boron sites of the h-BNNPs based on Lewis acid-base chemistry. The grafting of the alkylamines onto the h-BNNPs was confirmed using FTIR, XPS, TGA and (13)C SSNMR analyses. The crystalline and structural features of the alkylamine-functionalized h-BNNPs were studied using XRD and HRTEM analyses. The TGA and FTIR results revealed a higher grafting of octadecylamine (ODA) on the h-BNNPs compared to trioctylamine (TOA). The cohesive interaction between the alkyl chains grafted onto the h-BNNPs and the hydrocarbon chains of mineral lube base oil facilitates the dispersion of the alkylamine-functionalized h-BNNPs. The TOA-grafted h-BNNPs (h-BNNPs-TOA) exhibited long-term dispersion stability compared to the ODA-grafted h-BNNPs and this was attributed to a higher degree of van der Waals interactions between the octyl chains of the TOA molecules grafted onto the h-BNNPs and the hydrocarbon chains of the mineral lube base oil. The tribo-performance of the h-BNNPs-TOA as an additive to mineral lube base oil was evaluated in terms of the coefficient of friction and wear using ball-on-disc contact geometry. A minute dosing (0.02 mg mL(-1)) of h-BNNPs-TOA significantly improved the lubrication characteristics of the mineral lube base oil and showed a 35 and 25% reduction of friction and wear, respectively. The presence of boron and nitrogen on the worn scar of an aluminium disc, as deduced from elemental mapping, confirmed the formation of a tribo-chemical thin film of h-BN lamellae on the contact interfaces, which not only reduced the friction but also protected the contact interfaces against undesirable wear events.

Ethics in Science.

Ethics are a set of moral principles and values a civilized society follows. Doing science with principles of ethics is the bedrock of scientific activity. The society trusts that the results and the projected outcome of any scientific activity is based on an honest and conscientious attempt by the scientific community. However, during the last few decades, there has been an explosion of knowledge and the advent of digital age. We can access the publications of competitors with just a "click". The evaluation parameters have evolved a lot and are based on impact factors, h-index and citations. There is a general feeling that the scientific community is under a lot of pressure for fulfilling the criteria for upward growth and even retention of the positions held. The noble profession of scientific research and academics has been marred by the temptation to falsify and fabricate data, plagiarism and other unethical practices. Broadly speaking, the breach of ethics involves: plagiarism, falsification of data, redundant (duplicate) publication, drawing far-fetched conclusions without hard data, for early publicity, gift authorship (receiving as well as giving), not giving sufficient attention and consideration to scholars and post-docs as per the norms, self promotion at the cost of team-members, treating colleagues (overall all juniors) in a feudal way and Machiavellianism (cunningness and duplicity in general conduct and push to positions of power and pelf). Misconduct in Indian academics and science is also under a lot of focus. It is important and urgent that science, engineering, and health departments and institutions in our country have in place systems for education and training in pursuit of science with ethics by sound and professional courses in Responsible Conduct of Research. All research and academic institution must have the Office of Ethics for information, guidelines, training and professional oversight of conduct of research with the ethos and ethics of research.

The environmental and human effects of ptaquiloside-induced enzootic bovine hematuria: a tumorous disease of cattle.

In this review, we address the major aspects of enzootic bovine hematuria and have placed special emphasis on describing the etiology, human health implications, and advanced molecular diagnosis of the disease.Enzootic bovine hematuria (EBH) is a bovine disease characterized by the intermittent presence of blood in the urine and is caused by malignant lesions in the urinary bladder. This incurable disease is a serious malady in several countries across many continents. Accurate early-stage diagnosis of the disease is possible by applying advanced molecular techniques, e.g., detection of genetic mutations in the urine of cows from endemic areas. Use of such diagnostic approaches may help create an effective therapy against the disease.There is a consensus that EBH is caused primarily by animals consuming bracken fern (P. aquilinum) as they graze. The putative carcinogen in bracken is ptaquiloside(PT), a glycoside. However, other bracken constituents like quercetin, isoquercetin,ptesculentoside, caudatoside, astragalin, and tannins may also be carcinogenic.Studies are needed to identify the role of other metabolites in inducing urinary bladder carcinogenesis.The bovine papilloma virus is also thought to be an associated etiology in causing EBH in cattle. There is growing alarm that these fern toxins and their metabolites reach and contaminate the soil and water environment and that the carcinogen (PT)is transmitted via cow's milk to the human food chain, where it may now pose a threat to human health. An increased incidence of gastric and esophageal cancer has been recorded in humans consuming bracken ferns, and among those living for long periods in areas infested with bracken ferns.Although preliminary therapeutic vaccine trials with inactivated BPV-2 against EBH have been performed, further work is needed to standardize and validate vaccine doses for animals.

Necrotizing sarcoid granulomatosis.

PURPOSE OF REVIEW: Necrotizing sarcoid granulomatosis (NSG) is rare. Its various clinical and histological presentations are ambiguous and confusing. Although sometimes limited only to the lungs, other organ systems can be involved. The disease affects primarily women in their late forties but has been documented in children. RECENT FINDINGS: There are two schools of thought regarding the taxonomical position of NSG. Some believe that it is an independent entity, whereas others argue that it is just another manifestation of sarcoidosis. This article will review the available, current and evidence-based information about clinical and basic science aspects of NSG. SUMMARY: Diagnosis of NSG is perplexing; its pathogenesis is a dilemma. The disease is frequently confused with other processes including malignancy, Wegener's granulomatosis, hypersensitivity pneumonitis, sarcoidosis and lymphoid granulomatosis. Its symptoms are nonspecific and a histology finding of necrotizing granuloma has many causes. Although no specific management tool or strategies are advocated, steroids, surgical resection of localized disease or sometimes watchful waiting are recommended.

Cardiac sarcoidosis: diagnosis and management.

OPINION STATEMENT: Cardiac sarcoidosis can be life threatening if not promptly diagnosed and treated appropriately and aggressively. The diagnosis of myocardial disease is often difficult and circumstantial because there are no reliable diagnostic tests. Except for the finding of noncaseating granulomas on endomyocardial biopsy, most tests are limited and nonspecific. Therefore, the decision of initiating treatment is based on the patient's symptoms and the course of the disease, rather than on the presence of histologic confirmation. The goal of therapy is to prevent irreversible cardiomyopathy and to thwart the progression to heart transplantation. The mainstay of treatment is corticosteroids, although there are no large randomized trials analyzing corticosteroid use. The combination with other immunosuppressant agents, such as Methotrexate and Azathioprine, is initiated on the patient's failing or experiencing severe side effects from corticosteroids. While there are small studies proving the efficacy of tumor necrosis factor-inhibitors in cardiac sarcoidosis, more experience with these agents is needed. Catheter ablation or placement of implantable devices is indicated prophylactically in patients with severe ventricular tachyarrhythmias. Heart transplantation should be considered in patients with severe heart failure refractory to medical therapy. This article focuses on the current diagnostic tests and treatment recommendations for cardiac sarcoidosis.

Charge-driven interaction for adsorptive removal of organic dyes using ionic liquid-modified graphene oxide.

A facile approach is presented to synthesize the ionic liquid-grafted graphene oxide (GO-ImOH) for fast and efficient adsorptive removal of cationic dyes. A coupling reaction between the hydroxyl terminal of imidazolium ionic liquid and the carboxylic group of GO, yielded the GO-ImOH hybrid material. The higher surface negative charge (-32 mV) and excellent dispersibility make the GO-ImOH an efficient adsorbent for cationic dyes. The GO-ImOH showed excellent removal efficiency for methylene blue (cationic dye), whereas it could adsorb only 22% methyl orange (anionic dye). The GO-ImOH displayed significantly higher adsorptive removal capacity for cationic dye compared to that of GO adsorbent. The chemical and structural features of GO-ImOH and spectroscopic analyses (FTIR and Raman) of pristine and recovered GO-ImOH adsorbent suggested multiple adsorptive interaction pathways (electrostatic, π-cation, π-π interactions, and hydrogen linkages) between the GO-ImOH adsorbent and the dye molecules. The work paves a new direction for the development of ionic liquids-modified 2D nanomaterials for efficient and fast adsorptive removal of organic pollutants, where the adsorptive sites on the surface of 2D nanomaterials can be tuned by selecting the desired functionalities from a diversified library of cations and anions of ionic liquids.

Fruit waste-derived cellulose and graphene-based aerogels: Plausible adsorption pathways for fast and efficient removal of organic dyes.

A wide range of organic pollutants in industrial effluents, agricultural runoff, and domestic discharges are exacerbating water scarcity, leading to water-borne ailments, and adversely affecting the marine ecosystem and biodiversity. The efficient, sustainable, and cost-effective materials need to be addressed urgently for the removal of organic pollutants. Herein, ultra-light (0.018 g.cm-3) and highly porous (96.4%) composite aerogel is prepared by gelatinization of graphene oxide with fruit waste-derived cellulose. The macroscopic porosity generated by interconnecting cellulosic skeleton and graphene oxide sheets via hydrogen bonding network provided ample avenues for transport and diffusion of organic dyes-enriched wastewater throughout the cellulose-graphene oxide composite aerogel (CGA). Consequently, organic dyes are efficiently adsorbed by easily accessible surface sites distributed throughout the CGA. The size, charge, and chemical structure of organic dyes along with textural features and accessible surface active sites of CGA governed the adsorption process. The spectroscopic analyses based on FTIR, Raman, and XPS measurements suggest electrostatic, n-π, π-π, cation-π interactions, dipole-dipole hydrogen, and Yoshida hydrogen linkages as major interactive pathways for the adsorption of organic dyes by the CGA. Moreover, the composite aerogel furnished an excellent recyclability for the adsorptive removal of organic pollutants from wastewater. The present work promises the potential of 2D nanostructured layered materials and fruit-waste-derived composite aerogels for sustainable utilization in wastewater treatment, which can be an excellent step towards water security.

Surface Functionalization of WS2 Nanosheets with Alkyl Chains for Enhancement of Dispersion Stability and Tribological Properties.

Tungsten disulfide (WS2) exhibits intriguing tribological properties and has been explored as an excellent lubricious material in thin-film and solid lubricants. However, the poor dispersibility of WS2 has been a major challenge for its utilization in liquid lubricant applications. Herein, a top-down integrated approach is presented to synthesize oxygenated WS2 (WS2-O) nanosheets via strong acid-mediated oxidation and ultrasound-assisted exfoliation. The ultrathin sheets of WS2-O, comprising 4-7 molecular lamellae, exhibit oxygen/hydroxyl functionalities. The organosilanes having variable surface-active leaving groups (chloro and ethoxy) are covalently grafted, targeting the hydroxyl/oxygen functionalities on the surface of WS2-O nanosheets. The grafting of organosilanes is governed by the reactivity of chloro and ethoxy leaving groups. The DFT calculations further support the covalent interaction between the WS2-O nanosheets and organosilanes. The alkyl chain-functionalized WS2-O nanosheets displayed excellent dispersibility in mineral lube base oil. A minute dose of chemically functionalized-WS2 (0.2 mg.mL-1) notably enhanced the tribological properties of mineral lube oil by reducing the friction coefficient (52%) and wear volume (79%) for a steel tribopair. Raman analysis of worn surfaces revealed WS2-derived lubricious thin film formation. The improved tribological properties are attributed to ultralow thickness, stable dispersion, and low shear strength of chemically functionalized WS2 nanosheets, along with protective thin film formation over the contact interfaces of a steel tribopair. The present work opens a new avenue toward exploiting low-dimensional nanosheets for minimizing energy losses due to high friction.

Cardiac sarcoidosis: a review 2011.

PURPOSE OF REVIEW: Cardiac involvement in sarcoidosis is not always associated with a wide spread of disease, but when present, has been linked with a relatively poor prognosis. This review will delve into new genetic associations, recently reported clinical manifestations and complementary radiographic tools that aid with diagnosis and follow-up. RECENT FINDINGS: Clinical manifestations, diagnosis and management remain an intricate maze.Genetic predisposition and associations that include HLA class II molecules and polymorphisms in tumor necrosis factor-α have been reported due in part to weakened arguments suggesting autoimmune disorders or dysregulation. In addition, further symptomatologies have been reported that assist with diagnosis.Radiographic tools including Microvolt T wave alternans, cardiovascular magnetic resonance, late gadolinium enhancement and cardiac assist devices, recently being used, are shedding some light on the diagnostic challenges. SUMMARY: Cardiac involvement in sarcoidosis remains a challenging dilemma, relying on a combination of clinical findings and imaging abnormalities because no single diagnostic test has yet emerged with a high degree of specificity and sensitivity. Given its life-threatening nature, prompt establishment of a diagnosis, an aggressive management strategy and devices to prolong life should be pursued.

Radiation trends in trauma patients.

Today, computed tomography (CT) and other studies are used more often early in a trauma case than X-rays, exposing patients to more radiation. The long-term effects of radiation exposure (RE) in trauma patients are of great concern. Investigators randomly selected 60 patients (injury severity scores 15-25) each from the years 2000, 2003, and 2006. The cumulative effective dose (CED) was calculated from the RE of all X-rays and CTs performed during the patient's hospital stay. Total CED/patient increased from 15.97 (2000) to 16.67 (2003) to 23.27 mSv (2006); the increase from 2000 to 2006 was significant (P < 0.05). X-rays increased over the 6-year period from 9.6/patient (pt) to 11.4/pt to 15.4/pt. CT scans increased from 2.2/pt (15.19 mSv) to 3.5/pt (21.85 mSv, P < 0.05). The CED in children increased: 12.88 versus 13.17 versus 15.32 mSv/pt (P > 0.05). RE was 19.5 versus 22.0 versus 27.1 mSv in 16 to 45-year-olds compared with 15.5 versus 14.3 versus 27.0 mSv in older adults. Sixteen to 45-year-olds had significantly higher RE than children (P < 0.05). RE in the first hour and first 24 hours increased but not significantly (P > 0.05). CED increased from 2000 to 2006, due primarily from CT scans. Children had no significant CED increase during the same period and had lower RE than 16 to 45-year-old adults.

Role of non-operative management of spleen injury in patients with hemophilia: report of two patients with review of literature.

The non-operative management (NOM) of hemodynamically stable patients with splenic trauma is currently well accepted, yet non-operative therapy has rarely been attempted in coagulopathic patients. Two cases of successful NOM of splenic trauma in patients with hemophilia are presented with a review of the English medical literature.

Analysis of radiation exposure in trauma patients at a level I trauma center.

BACKGROUND: Trauma patients are exposed to potentially high levels of low-dose radiation during radiologic studies. OBJECTIVES: To assess the cumulative effective dose (CED) of radiation exposure (RE) in 177 successive patients admitted to a trauma service from January 1 through February 28, 2006. RESULTS: Patients received a total of 1505 radiographs and 400 computed tomography (CT) scans in the study period. The CED was 14.56 mSv (0.97 mSv radiographs, 13.59 mSv CT scans) per patient total length of stay (LOS). CED averaged 8.66 mSv in the first hour and 11.76 mSv in the first 24 h after arrival. The most commonly performed CT scan was brain (n = 147), followed by abdomen and pelvis (n = 80), and cervical spine (n = 69). CT scans of the brain and cervical spine were the most commonly performed combined imaging tests (35%). Twelve percent of patients received no radiographs, and 15% received no CT scans. Six or more CT scans were done in 6% of patients. RE increased with longer LOS (> 6 days vs. 3-5 days vs. 1 day, p < 0.05). "Pan-scans" (a combination of CTs of the brain, cervical spine, chest, abdomen, and pelvis) were done in 13% (n = 23) of patients. There was a higher total RE from CT scans (25.09 mSv ± 19.48 mSv vs. 4.93 mSv ± 14.20 mSv) in patients with injury severity score (ISS) > 9 vs. ≤ 9 ( p < 0.0001). First hour and first 24-h RE rates from radiographs were lower in patients younger than 15 years vs. 15-45 years and older-than-45-year age cohorts (p < 0.05). CONCLUSIONS: In this study, CED was 14.56 mSv per patient. CT scans accounted for 21% of radiologic studies and 93% of CED. There was a higher CED rate in patients with ISS > 9 and longer LOS.

A pragmatic approach to diagnosing and treating neurosarcoidosis in the 21st century.

PURPOSE OF REVIEW: Neurosarcoidosis may be a serious complication of sarcoidosis. As the presentation of neurosarcoidosis is manifold, solitary nervous system sarcoidosis without systemic activity remains a difficult diagnosis. Appropriate treatment may be a dilemma. RECENT FINDINGS: Most neurosarcoidosis patients present with neurological symptoms as the first manifestation. Whole-body fluorodeoxyglucose positron emission tomography has been found useful in neurological patients suspected of sarcoidosis. Small-fiber neuropathy is commonly associated with sarcoidosis and can cause significant morbidity to afflicted patients. New drugs such as antitumor necrosis factor alpha have been proven valuable in the treatment of neurosarcoidosis in different locations. Progressive multifocal leucencephalopathy should be considered in neurosarcoid patients, especially when treatment fails. SUMMARY: In this paper an update on clinical manifestations of neurosarcoidosis, diagnostic dilemmas, and therapeutic options is provided.

Gastric sarcoidosis and review of the literature.

Sarcoidosis is a systemic disease with a 90% predilection for the lungs, but any organ can be involved. Gastrointestinal involvement is rare. Within the gastrointestinal system, gastric involvement is the most common. When this organ system is involved, it can be a feature of systemic disease or an isolated case. Gastrointestinal sarcoid can resemble a broad spectrum of other disease processes; thus, it is important for health care providers to be familiar with the various gastrointestinal manifestations. Patients can have subclinical symptoms or have symptoms of epigastric pain, nausea, vomiting, and hematemesis. We present 2 cases of gastric sarcoid and a MEDLINE search of 44 reported cases of gastric sarcoid based on a compatible history and the demonstration of noncaseating granulomas. We describe the clinical manifestations of symptomatic gastric sarcoid in relation to the endoscopic findings.

Stab wound of the neck with contralateral hemo-pneumothorax.

A rare case of stab wound of the neck with contralateral hemo-pneumothorax with a mediastinal shift is presented. After tube thoracostomy and computed tomography, the patient had angiographic coil embolotherapy of transected internal mammary artery (IMA). Subsequently, neck exploration with the repair of sternocleidomastoid was done. The patient underwent decortication on the 11(th) post-operative day for persistent residual hemothorax. IMA transection most often occurs from ipsilateral parasternal stab wounds and rarely from iatrogenic trauma. It is important to recognize the presentation of this rare entity as appropriate aggressive diagnostic and therapeutic interventions may be warranted.

Chemical composition and antibacterial activity of essential oils of Lantana camara, Ageratum houstonianum and Eupatorium adenophorum.

Essential oils have applications in folk medicine, food preservation, and as feed additives. The essential oils of Lantana camara Linn. (Verbenaceae), Ageratum houstonianum Mill. (Asteraceae) and Eupatorium adenophorum Spreng. (Asteraceae) were analyzed by Gas chromatography-mass spectrometry (GCMS). In L. camara oil, of the total identified (83.91%) volatile constituents, five constituents [3,7,11-trimethyl-1,6,10-dodecatriene (28.86%), beta-caryophyllene (12.28%), zingiberene (7.63%), gamma-curcumene (7.50%) and alpha-humulene (3.99%)] represented the major ones. In A. houstonianum oil, among the total identified volatile constituents (94.51%), three [precocene-II (52.64%), precocene-I (22.45%) and beta-caryophyllene (9.66%)] represented the major ones. In E. adenophorum oil, of the total identified volatile constituents (84.95%), six [1-napthalenol (17.50%), alpha-bisabolol (9.53%), bornyl acetate (8.98%), beta-bisabolene (6.16%), germacrene-D (5.74%) and alpha- phellandrene (3.85%)] represented the major ones. The antibacterial activity expressed as Minimum Bactericidal Concentration (MBC) (microg/mL) was determined by the broth dilution method. The essential oil of E. adenophorum had antibacterial activity against Arthrobacter protophormiae, Escherichia coli, Micrococcus luteus, Rhodococcus rhodochrous, and Staphylococcus aureus with MBC values of 200, 100, 100, 12.5, and 200, respectively. The essential oil of A. houstonianum showed antibacterial activity against M. luteus and R. rhodochrous with MBC of 100 and 12.5, but not against A. protophormiae, E. coli, and S. aureus. The essential oil of L. camara showed antibacterial activity against A. protophormiae, M. luteus, R. rhodochrous and S. aureus with MBC of 50, 25, 12.5, and 200, respectively, but not against E. coli. MBC was lowest for R. rhodochrous for all the three essential oils.

Infection risk stratification in total knee joint arthroplasty using a new scoring system.

Periprosthetic joint infection (PJI) is a catastrophic complication of total knee arthroplasty (TKA) adding significant costs to the health care system with increasing morbidity and mortality. The goal of this study was to develop a prognostic scoring system that could risk-stratify patients undergoing TKA for the risk of PJI. The study included 150 patients who underwent primary TKA from June 2012 to February2016. There were 60 patients in group I who were not risk stratified using the scoring system, while 90 patients were assigned to group II and were prospectively assigned scores based on the scoring system. Points were assigned for each pre-op variable and a scoring chart was developed. Group II patients scoring 4 or more were counseled to optimize their modifiable risk factors before proceeding with surgery. Retrospective chart review was done for patients in group I to find out their risk score for the study purpose. Nine out of 60 patients in group I were found to have score above 4 based on the chart review, of which 4 patients got infected (P<0.05). None of the group II patients got infected after TKA. In conclusion, our scoring system is an objective scoring system for preoperative risk stratification of patients undergoing TKA, thus helping identification and optimization of the risk factors preoperatively to decrease the risk of PJI.

Structural-Defect-Mediated Grafting of Alkylamine on Few-Layer MoS2 and Its Potential for Enhancement of Tribological Properties.

Two-dimensional transition-metal dichalcogenides possess inherent structural characteristics that can be harnessed for enhancement of tribological properties by making them dispersible in lube media. Here, we present a hydrothermal approach to preparing MoS2 nanosheets comprising 4-10 molecular lamellae. A structural-defect-mediated route for grafting of octadecylamine (ODA) on MoS2 nanosheets is outlined. The unsaturated d orbitals of Mo at the sulfur vacancies on the MoS2 surface are coupled with the electron-rich nitrogen center of ODA and yield ODA-functionalized MoS2 (MoS2-ODA). The MoS2-ODA nanosheets exhibit good dispersibility in lube base oil and are used as an additive (optimized dose: 0.1 mg·mL-1) to mineral oil. It is shown that even at low concentration, MoS2-ODA nanosheets significantly reduce the friction (48%) and wear (44%). Microscopy (field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM)) and spectroscopy (Raman and elemental mapping) analyses of worn scars revealed the formation of MoS2-based protective thin films for lowering of friction and wear. This work, therefore, presents a pathway for low-friction lubricants by deploying functionalized low-dimensional material systems.