Postharvest handling of ethylene with oxidative and absorptive means.

Fruit ripening is an unfolding of a series of genetically-programmed modifications and tend to be highly orchestrated irrevocable phenomenon mediated by ethylene. Phytohormone ethylene also leads to over-ripening, senescence, loss of texture, microbial attack, reduced post-harvest life and other associated problems during storage and transportation of fruits. Its harmful impacts on fresh fruits, vegetables, and ornamentals result in substantial product losses even up to 80%. Curbing of this inevitable menace is therefore need of the hour. Accrual of ethylene in packaging system should fundamentally be ducked to extend the shelf-life and uphold an adequate superiority of perishables in visual and organoleptic terms. The current review discusses about properties, factors affecting and impact of ethylene, intimidation of its impact at gene vis-à-vis activity level using gene-modification/inhibition techniques, chemical/physical in conjunction with other suitable approaches. It also entails the most commercially cultivated approaches worldwide viz. KMnO4-based oxidation together with adsorption-based scrubbing of ethylene in thorough details. Future ethylene removal strategies should focus on systematic evaluation of KMnO4-based scavenging, exploring the mechanism of adsorption, adsorbent(s) behavior in the presence of other gases and their partial pressures, volatiles, temperature, relative humidity, development of hydrophobic adsorbents to turn-up under high RH, regeneration of adsorbent by desorption, improvement in photocatalytic oxidation etc. and further improvements thereof. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05777-1.

Inter-observer agreement among specialists in the diagnosis of oral potentially malignant disorders and oral cancer using store-and-forward technology.

OBJECTIVES: Oral cancer is a leading cause of morbidity and mortality. Screening and mobile Health (mHealth)-based approach facilitates early detection remotely in a resource-limited settings. Recent advances in eHealth technology have enabled remote monitoring and triage to detect oral cancer in its early stages. Although studies have been conducted to evaluate the diagnostic efficacy of remote specialists, to our knowledge, no studies have been conducted to evaluate the consistency of remote specialists. The aim of this study was to evaluate interobserver agreement between specialists through telemedicine systems in real-world settings using store-and-forward technology. MATERIALS AND METHODS: The two remote specialists independently diagnosed clinical images (n=822) from image archives. The onsite specialist diagnosed the same participants using conventional visual examination, which was tabulated. The diagnostic accuracy of two remote specialists was compared with that of the onsite specialist. Images that were confirmed histopathologically were compared with the onsite diagnoses and the two remote specialists. RESULTS: There was moderate agreement (k= 0.682) between two remote specialists and (k= 0.629) between the onsite specialist and two remote specialists in the diagnosis of oral lesions. The sensitivity and specificity of remote specialist 1 were 92.7% and 83.3%, respectively, and those of remote specialist 2 were 95.8% and 60%, respectively, each compared with histopathology. CONCLUSION: The diagnostic accuracy of the two remote specialists was optimal, suggesting that "store and forward" technology and telehealth can be an effective tool for triage and monitoring of patients. CLINICAL RELEVANCE: Telemedicine is a good tool for triage and enables faster patient care in real-world settings.

ITO with embedded silver grids as transparent conductive electrodes for large area organic solar cells.

In this work, development of semi-transparent electrodes for efficient large area organic solar cells (OSCs) has been demonstrated. Electron beam evaporated silver grids were embedded in commercially available ITO coatings on glass, through a standard negative photolithography process, in order to improve the conductivity of planar ITO substrates. The fabricated electrodes with embedded line and square patterned Ag grids reduced the sheet resistance of ITO by 25% and 40%, respectively, showing optical transmittance drops of less than 6% within the complete visible light spectrum for both patterns. Solution processed bulk heterojunction OSCs based on PTB7:[70]PCBM were fabricated on top of these electrodes with cell areas of 4.38 cm2, and the performance of these OSCs was compared to reference cells fabricated on pure ITO electrodes. The Fill Factor (FF) of the large-scale OSCs fabricated on ITO with embedded Ag grids was enhanced by 18% for the line grids pattern and 30% for the square grids pattern compared to that of the reference OSCs. The increase in the FF was directly correlated to the decrease in the series resistance of the OSCs. The maximum power conversion efficiency (PCE) of the OSCs was measured to be 4.34%, which is 23% higher than the PCE of the reference OSCs. As the presented method does not involve high temperature processing, it could be considered a general approach for development of large area organic electronics on solvent resistant, flexible substrates.

Implementation of a workplace intervention using financial rewards to promote adherence to physical activity guidelines: a feasibility study.

BACKGROUND: We designed and implemented the Brigham and Women's Wellness Initiative (B-Well), a single-arm study to examine the feasibility of a workplace program that used individual and team-based financial incentives to increase physical activity among sedentary hospital employees. METHODS: We enrolled sedentary, non-clinician employees of a tertiary medical center who self-reported low physical activity. Eligible participants formed or joined teams of three members and wore Fitbit Flex activity monitors for two pre-intervention weeks followed by 24 weeks during which they could earn monetary rewards. Participants were rewarded for increasing their moderate-to-vigorous physical activity (MVPA) by 10% from the previous week or for meeting the Centers for Disease Control and Prevention (CDC) physical activity guidelines (150 min of MVPA per week). Our primary outcome was the proportion of participants meeting weekly MVPA goals and CDC physical activity guidelines. Secondary outcomes included Fitbit-wear adherence and factors associated with meeting CDC guidelines more consistently. RESULTS: B-Well included 292 hospital employees. Participants had a mean age of 38 years (SD 11), 83% were female, 38% were obese, and 62% were non-Hispanic White. Sixty-three percent of participants wore the Fitbit ≥4 days per week for ≥20 weeks. Two-thirds were satisfied with the B-Well program, with 79% indicating that they would participate again. Eighty-six percent met either their personal weekly goal or CDC physical activity guidelines for at least 6 out of 24 weeks, and 52% met their goals or CDC physical activity guidelines for at least 12 weeks. African Americans, non-obese subjects, and those with lower impulsivity scores reached CDC guidelines more consistently. CONCLUSIONS: Our data suggest that a financial incentives-based workplace wellness program can increase MVPA among sedentary employees. These results should be reproduced in a randomized controlled trial. TRIAL REGISTRATION: Clinicaltrials.gov, NCT02850094 . Registered July 27, 2016 [retrospectively registered].

Association of MRI findings and expert diagnosis of symptomatic meniscal tear among middle-aged and older adults with knee pain.

BACKGROUND: Our aim was to examine the association between an expert clinician's impression of symptomatic meniscal tears and subsequent MRI in the context of middle-aged and older adults with knee pain. METHODS: Patients older than 45 were eligible for this IRB-approved substudy if they had knee pain, had not undergone MRI and saw one of two orthopaedic surgeons experienced in the diagnosis of meniscal tear. The surgeon rated their confidence that the patient's symptoms were due to meniscal tear. The patient subsequently had a 1.5 or 3.0 T MRI within 6 months. We examined the association between presence of meniscal tear on MRI and the surgeon's confidence that the knee pain was due to meniscal tear using a χ(2) test for trend. RESULTS: Of 84 eligible patients, 63% were female, with a mean age of 64 years and a mean BMI of 27. The surgeon was confident that symptoms emanated from a tear among 39%. The prevalence of meniscal tear on MRI overall was 74%. Among subjects whose surgeon indicated high confidence that symptoms were due to meniscal tear, the prevalence was 80% (95% CI 63-90%). Similarly, the prevalence was 87% (95% CI 62-96%) among those whose surgeon had medium confidence and 64% (95% CI 48-77%) among those whose surgeon had low confidence (p = 0.12). CONCLUSION: Meniscal tears were frequently found on MRI even when an expert clinician was confident that a patient's knee symptoms were not due to a meniscal tear, indicating that providers should use MRI sparingly and cautiously to confirm or rule out the attribution of knee pain to meniscal tear.

Association between activity limitations and pain in patients scheduled for total knee arthroplasty.

BACKGROUND: Historically, persons scheduled for total knee arthroplasty (TKA) have reported severe pain with low demand activities such as walking, but recent data suggests that TKA recipients may have less preoperative pain. Little is known about people who elect TKA with low levels of preoperative pain. To better understand current TKA utilization, we evaluated the association between preoperative pain and difficulty performing high demand activities, such as kneeling and squatting, among TKA recipients. METHODS: We used baseline data from a randomized control trial designed to improve physical activity following TKA. Prior to TKA, participants were categorized according to Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain scores: Low (0-25), Medium (26-40), and High (41-100). Within each group, limitations in both low demand and high demand activities were assessed. RESULTS: The sample consisted of 202 persons with a mean age of 65 (SD 8) years; 21 %, 34 %, and 45 % were categorized in the Low, Medium, and High Pain groups, respectively. Of the Low Pain group, 60 % reported at least one of the following functional limitations: limited flexion, limp, limited walking distance, and limitations in work or housework. While only 12 % of the Low Pain group reported at least moderate pain with walking on a flat surface, nearly all endorsed at least moderate difficulty with squatting and kneeling. CONCLUSIONS: A substantial number of persons scheduled for TKA report Low WOMAC Pain (≤25) prior to surgery. Persons with Low WOMAC Pain scheduled for TKA frequently report substantial difficulty with high demand activities such as kneeling and squatting. Studies of TKA appropriateness and effectiveness for patients with low WOMAC Pain should include measures of these activities. TRIAL REGISTRATION: Identifier NCT01970631 ; Registered 23 October 2013.

Dual carbon isotope-based brown carbon aerosol characteristics at a high-altitude site in the northeastern Himalayas: Role of biomass burning.

PM2.5 samples (n = 34) were collected from January to April 2017 over Shillong (25.7°N, 91.9°E; 1064 m amsl), a high-altitude site situated in the northeastern Himalaya. The main aim was to understand the sources, characteristics, and optical properties of local vs long-range transported carbonaceous aerosols (CA) using chemical species and dual carbon isotopes (13C and 14C). Percentage biomass burning (BB)/biogenic fraction (fbio, calculated from 14C) varied from 67 to 92 % (78 ± 7) and correlated well with primary BB tracers like f60, and K+, suggesting BB as a considerable source. Rain events are shown to reduce the fbio fraction, indicating majority of BB-derived CA are transported. Further, δ13C (-26.6 ± 0.4) variability was very low over Shillong, suggesting it's limitations in source apportionment over the study region, if used alone. Average ratio of absorption coefficient of methanol-soluble BrC (BrCMS) to water-soluble BrC (BrCWS) at 365 nm was 1.8, indicating a significant part of BrC was water-insoluble. A good positive correlation between fbio and mass absorption efficiency of BrCWS and BrCMS at 365 nm with the higher slope for BrCMS suggests BB derived water-insoluble BrC was more absorbing. Relative radiative forcing (RRF, 300 to 2500 nm) of BrCWS and BrCMS with respect to EC were 11 ± 5 % and 23 ± 16 %, respectively. Further, the RRF of BrCMS was up to 60 %, and that of BrCWS was up to 22 % with respect to EC for the samples with fbio ≥ 0.85 (i.e., dominated by BB), reflecting the importance of BB in BrC RRF estimation.

Jaws of knowledge: an analysis of temporomandibular joint insights in dental training-a quasi-experiment study.

Objectives: To access the knowledge of undergraduate and postgraduate students of the dental college on basic anatomy, physiology, clinical examination, and pathology of the temporomandibular joint (TMJ). Materials and Methods: A total of 610 undergraduate and postgraduate students of dental college, were included in this study. The questionnaire was pretested for validation and distributed online through Google forms. Results: A pairwise comparison showed that the percentage of correct answers for interns significantly differed from that of IV Bachelor of Dental Surgery (P=0.050) and postgraduate students (P=0.048) (below average: up to 6 correct answers, good: 7-11 correct answers, excellent: 12 or more correct answers). Conclusion: TMJ diseases are common in daily life but frequently go undiagnosed and untreated due to a lack of clinical expertise. This demonstrates the necessity of providing instructions that give students in-depth knowledge and abilities for TMJ issues in clinical practice.

Pathways to Upscaling Highly Efficient Organic Solar Cells Using Green Solvents: A Study on Device Photophysics in the Transition from Lab-to-Fab.

As the rise of nonfullerene acceptors (NFA) has allowed lab-scale organic solar cells (OSC) to reach 20% efficiency, translating these devices into roll-to-roll compatible fabrication still poses many challenges for researchers. Among these are the use of green solvent solubility for large-scale manufacture, roll-to-roll compatible fabrication, and, not least, information on charge carrier dynamics in each upscaling step, to further understand the gap in performance. In this work, the reproducibility of champion devices using slot-die coating with 14% power conversion efficiency (PCE) is demonstrated, under the condition that the optimal thickness is maintained. It is further shown that for the donor:acceptor (D:A) blend PM6:Y12, the processing solvent has a more significant impact on charge carrier dynamics compared to the deposition technique. It is found that the devices processed with o-xylene feature a 40% decrease in the bimolecular recombination coefficient compared to those processed with CB, as well as a 70% increase in effective mobility. Finally, it is highlighted that blade-coating yields devices with similar carrier dynamics to slot-die coating, making it the optimal choice for lab-scale optimization with no significant loss in translation toward up-scale.

Development of meat-bone separator for small scale fish processing.

The belt and drum type meat-bone separator was developed for small-scale fish processing and evaluated using Tilapia fish (Oreochromis mossambicus) in terms of capacity, yield, percentage yield, bone content, colour and power consumption. It consists of a perforated drum (3 mm), single phase electric motor, speed reduction gear box and drive system. The machine was evaluated using two food grade belt viz., natural rubber (Belt A-35 shore) and canvas belt (Belt B-65 shore) for three drum speeds. The machine capacity was in the range of 45.59 to 68.54 kg h(-1) for belt A with a yield of 1.148, 1.069 and 1.066 kg, and 49.13 to 78.13 kg h(-1) for belt B with a yield of 1.253, 1.312 and 1.269 kg at drum speeds of 14, 20 and 24 rpm, respectively. For belt A, the highest yield (1.148 kg) was obtained at 14 rpm drum speed which was 63.78% on dressed weight basis and for belt B, the highest yield (1.312 kg) was obtained at 20 rpm drum speed which was 72.89% on dressed weight basis. The increased number of passes for meat recovery increased the chances of insertion of bone fragments into minced meat and decreased the colour values (L-a-b). The total energy consumption did not vary significantly.

Characterization of paddy-residue burning derived carbonaceous aerosols using dual carbon isotopes.

A large scale paddy-residue burning (PRB) happens every year in the northwest Indo-Gangetic Plain (IGP) during the post-monsoon season, and winds transport pollutants from the source region up to the northern Indian Ocean affecting air quality of the IGP and marine region. In this study, day-night pairs of fine aerosol samples (n = 69) were collected during October-November over Patiala (30.2°N, 76.3°E, 250 m amsl), a site located in the source region of PRB. Carbonaceous aerosols (CA) were characterised using chemical species and dual carbon isotopes (13C and 14C) to estimate bio vs non-bio contributions and understand their characteristics. Percentage of bio fraction (fbio, estimated using 14C) in CA varied from 74 % to 87 % (avg: 80 ± 3) during days and 71 % to 96 % (avg: 85 ± 7 %) during nights. Further, the fbio was found to be better correlated with aerosol mass spectrometer derived f60 compare to levoglucosan (LG) or nssK+, suggesting f60 a useful proxy for PRB. The δ13C varied from -27.7 ‰ to -26.0 ‰ (avg: -27.0 ± 0.4 ‰) and - 28.7 ‰ to -26.4 ‰ (avg: -27.5 ± 0.7 ‰) during day and night, respectively. Measured δ13C of the samples was found to be more enriched than expected by 0.3 to 2.0 ‰, indicating the presence of aged CA also in Patiala even during PRB period. From fbio versus δ13C correlation, and from Miller-Trans plot, δ13C of PRB is found to be -28.9 ± 1.1 ‰, which also infers that Miller-Trans plot can be used to understand source isotopic signature in the absence of radiocarbon measurements in aerosols. Further, the characteristics ratios of organic carbon (OC) to elemental carbon (EC) (11.9 ± 4.1), LG to potassium (K+) (0.84 ± 0.15), OC/LG (19.7 ± 2.0) and K+/EC (0.75 ± 0.27) were calculated by considering samples with fbio higher than 0.90, which can be used for source apportionment studies. Such studies are crucial in assessing the effects of PRB on regional air quality and climate.

Development of Niosomal Vesicles Loaded Mometasone Furoate Gel for Transdermal Delivery and its Evaluation.

BACKGROUND: Mometasone Furoate (MF) is a corticosteroid (glucocorticoid) used to treat eczema, psoriasis, allergies, and rash on the skin; also used to reduce itching, redness, and swelling (inflammation). It has been reported that the bioavailability of MF is less than 11% when given via the nasal route. Encapsulating the drug in niosomes can improve the active pharmaceutical ingredient's bioavailability by enhancing both physical and biological stability. OBJECTIVE: The goal of the study is to develop, a non-ionic surfactant-based vesicular system, by loading mometasone furoate, and introducing it into a gel-based formulation by utilizing an appropriate gelling agent, and performing its evaluation. METHODS: The niosome vesicle was prepared by vacuum rotary evaporation method (Thin film hydration method). Gel was prepared using the dispersion method and in-vitro drug diffusion studies using Franz-diffusion cells. RESULTS: According to the results of the experiments conducted for the study, Mometasone Furoate niosomal gel was prepared utilizing Mometasone Furoate niosomes that were made using the thin film hydration process, Cholesterol, and Span 60, and loaded in various amounts of Carbopol as a geling agent. The niosomes' zeta potential was found to be -24 mV, showing that the formulation is stable. The polydispersity index (PDI) was found to be 0.409 and the average size of niosomes to be 252.7 nm. The performance of the gel of the optimized formulations containing 2% Carbopol showed in vitro diffusion for 7 hours and an increased flux rate as compared to the plain MF. CONCLUSION: The experiments carried out during the study led to the conclusion that the thin-film hydration method was suitable for the formation of the MF-niosomes by using Span 60 and Cholesterol (2:1). The gel formulation containing 2% Carbopol indicated better in vitro diffusion following the Higuchi model across all niosomal gel formulations. Niosomal gel can be regarded as the best vesicular carrier for the efficient distribution of mometasone furoate via the transdermal route.

Formulation Of Benzoyl Peroxide Microsponge-Based Transdermal Gel For Acne Infection And Its Evaluation.

BACKGROUND: Benzoyl peroxide is a peroxide with antibacterial, irritating, keratolytic, comedolytic, and anti-inflammatory properties. When benzoyl peroxide is applied topically, it breaks down and releases oxygen, which kills the germs of Propionibacterium acnes. Benzoyl peroxide's irritating impact causes an increase in epithelial cell turnover, which causes the skin to peel and aids in the healing of comedones. Treatment for acne vulgaris involves the use of benzoyl peroxide. OBJECTIVE: The research is aimed at studying the formulation of Microsponge gel preparation of benzoyl peroxide by using Carbopol 934 as a gelling agent and evaluation of microsponge gel formulation for its physicochemical properties. METHODS: Microsponges of Anti-acne agent benzoyl peroxide drug were prepared by quasi-emulsion method, and in-vitro drug release using a suitable membrane model using a simple diffusion cell. RESULT: Prior to drying, the microsponge was filtered and rinsed using distilled water. Formulation containing benzoyl peroxide and Eudragit RS100 with a ratio of 1:4 showed a high 87.5% drug content and 78.20 % yield. The drug content of the microsponge gel was found to be 84%. Microbiological study on S. aureus was conducted by the cylinder cup method and found good results. The in-vitro diffusion of microsponge formulations was sustained for 8 hours. The drug release rate for Eudragit RS-100 was reported to be 88.87% after 8 hours based on the polymer: drug ratio (4:1). CONCLUSION: The quasi-emulsion solvent diffusion method was used to successfully prepare benzoyl peroxide microsponges using Eudragit RS100, Ethyl Cellulose, and HPMC K4M as polymers. The formulations with the highest medication concentration were made with the porous polymer Eudragit RS100.

Inter-observer agreement among specialists in the diagnosis of Oral Potentially Malignant Disorders and Oral Cancer using Store-and-Forward technology.

Oral Cancer is one of the most common causes of morbidity and mortality. Screening and mobile Health (mHealth) based approach facilitates remote early detection of Oral cancer in a resource-constrained settings. The emerging eHealth technology has aided specialist reach to rural areas enabling remote monitoring and triaging to downstage Oral cancer. Though the diagnostic accuracy of the remote specialist has been evaluated, there are no studies evaluating the consistency among the remote specialists, to the best of our knowledge. The purpose of the study was to evaluate the interobserver agreement between the specialists through telemedicine systems in real-world settings using store and forward technology. Two remote specialists independently diagnosed the clinical images from image repositories, and the diagnostic accuracy was compared with onsite specialist and histopathological diagnosis when available. Moderate agreement (k = 0.682) between two remote specialists and (k = 0.629) between the onsite specialist and two remote specialists in diagnosing oral lesions. The sensitivity and specificity of remote specialist 1 were 92.7% and 83.3%, whereas remote specialist 2 was 95.8% and 60%, respectively, compared to histopathology. The store and forward technology and telecare can be effective tools in triaging and surveillance of patients.

Efficiency-Enhanced Scalable Organic Photovoltaics Using Roll-to-Roll Nanoimprint Lithography.

Invited for this month's cover is the group of Prof. Morten Madsen, University of Southern Denmark, together with Stensborg A/S and Dr. Shalev's group at the Ben-Gurion University of the Negev. The image shows the integration of Roll-to-Roll (R2R) light-management foils to enhance efficiency of R2R organic photovoltaics. The Full Paper itself is available at 10.1002/cssc.202101611.

Efficiency-Enhanced Scalable Organic Photovoltaics Using Roll-to-Roll Nanoimprint Lithography.

Light-trapping nanostructures have for decades been researched as a route to enhance the performance of organic solar cells (OSCs). Whereas the power conversion efficiencies (PCEs) of OSCs have reached above 18 %, industrially compatible devices made by scalable processing in air, using only nontoxic solvents and materials, have shown significantly lower performance values. Although light-trapping nanostructures may improve this, the methods for integrating the nanostructures are typically not compatible with industrial scale up. In this work, scalable, industrially compatible, nonfullerene-based OSCs are developed with integrated light-trapping nanostructures at the back electrodes in the devices. The OSCs are made by using scalable roll-to-roll (R2R) and sheet-to-sheet (S2S) processes and the nanostructures are made by using roll-to-plate (R2P) nanoimprint lithography. A fully scalable solution is thereby developed for industrially compatible nanostructured OSCs. The nanostructured devices show enhancements in PCE up to 25 % compared to reference cells, owing to an enhancement in the short-circuit current density (15 %) by enhanced absorption, and improved charge carrier extraction leading to an enhancement in the fill factor (7 %). Optical modeling is utilized to verify the optical effect of the nanostructures. The best devices attain a PCE of 6.5 %, which is the highest reported efficiency for air-processed slot-die coated ITO-free flexible PBDB-T : ITIC devices, here using nontoxic solvents.

Isolated Infratemporal Fossa Desmoid Fibromatosis: A Rare Case Report and Review of Literature.

Desmoid fibromatosis (DF) arising from musculoaponeurotic structures rarely affects the head and neck region with the abdomen being the most common site of origin. These are benign tumors with locally infiltrative nature usually presenting as painless swellings that are rapidly growing. The infratemporal fossa DF is an extremely rare location with few clinical reports. This article discusses the management of a 2-year-old child with DF of the infratemporal fossa (ITF) along with literature review.

Radiomorphometric Indices and their Relation to Alveolar Bone Loss: A Panoramic Radiographic Study.

Aim: To assess the influence of gender and age on different parameters of alveolar bone loss using specific radiomorphometric indices on panoramic radiographs to aid in identifying patients with possible low bone mineral density (BMD). Materials and Methods: The present cross-sectional study included 80 subjects in whom mandibular cortical index (MCI), mandibular cortical width (MCW), panoramic mandibular index (PMI), alveolar bone loss (ABL), and bone height in 1st premolar (Hp) and 1st molar (Hm) were assessed to evaluate the alveolar bone loss. Results: The findings of the present study revealed a significant association between MCI and age for females with C2 and C3 categories being more common with advancing age. Also, a significant difference could be seen in relation to gender (p-value = 0.0315) for MCW with a concomitant decrease in values of MCW in females >60 years of age. The vertical bone height of the edentulous mandible at 1st premolar (Hp) (p-value = 0.0071) and 1st molar (Hm) (p-value = 0.0044) regions were also found to be more in males than females. Conclusion: Panoramic radiographic measurements provided valuable information for alveolar bone loss in terms of gender and age based on specific radiomorphometric parameters.

Indirect enantioresolution of (R,S)-mexiletine by reversed-phase high-performance liquid chromatography via diastereomerization with [(S,S)-O,O'-di-p-toluoyl tartaric acid anhydride], (S)-naproxen and nine chiral reagents synthesized as variants of Marfey's reagent.

Eleven chiral derivatizing reagents (CDRs) were used for preparation of diastereomers of (R,S)-mexiletine containing a primary amino group in close proximity to the stereogenic center. One anhydride, namely [(S,S)-O,O'-di-p-toluoyl tartaric acid anhydride] was synthesized and (S)-naproxen was used as such as the chiral derivatizing reagent. The other nine CDRs were synthesized by substituting one of the fluorine atoms in 1,5-difluoro-2,4-dinitrobenzene with six amino acid amides and three amino acids. The diastereomers were separated by reversed-phase high-performance liquid chromatography. The method was validated for linearity, accuracy, limit of detection and limit of quantification. The limit of detection was found in the range of 10-30 pmol.

Silent cardiac comorbidity in arthroplasty patients: an unusual suspect?

We studied 109 patients who were subjected to dobutamine stress echocardiography (DSE) for preoperative cardiac risk assessment before undergoing elective primary hip and knee arthroplasty. Patients were selected for DSE based on several criteria. There were 16 patients with history of ischemic heart disease and 93 patients without. Seven of the 93 patients showed a positive DSE test result, of which 5 developed postoperative cardiac events (P = .00). This study clearly shows that serious "silent" cardiac comorbidity can exist even in so-called healthier patients undergoing routine hip and knee arthroplasty. We believe that identifying these patients and treating them before arthroplasty can significantly improve the overall outcome of the surgery.