Conformal elasticity of mechanism-based metamaterials

Deformations of conventional solids are described via elasticity, a classical field theory whose form is constrained by translational and rotational symmetries. However, flexible metamaterials often contain an additional approximate symmetry due to the presence of a designer soft strain pathway. Here we show that low energy deformations of designer dilational metamaterials will be governed by a scalar field theory, conformal elasticity, in which the nonuniform, nonlinear deformations observed under generic loads correspond with the well-studied—conformal—maps. We validate this approach using experiments and finite element simulations and further show that such systems obey a holographic bulk-boundary principle, which enables an analytic method to predict and control nonuniform, nonlinear deformations. This work both presents a unique method of precise deformation control and demonstrates a general principle in which mechanisms can generate special classes of soft deformations.

Successive Grinding and Polishing Effect on the Retained Austenite in the Surface of 42CrMo4 Steel

Low-alloy 42CrMo4 steels were studied by 57Fe Mössbauer spectroscopy (MS), X-ray diffractometry (XRD), and Energy Dispersive X-ray Spectroscopy (EDS) measurements. The investigations were performed on metallographic samples, which were subjected to a series of successive grinding and polishing with a progressively finer grit. Conversion X-ray Mössbauer spectroscopy (CXMS) was used to determine the occurrence of austenite in steel samples. It is a unique method detecting the austenite content very sensitively. Six samples with different surface preparation were investigated, starting with 4.8% of austenite on an as-cut sample, and a large decrease in the retained austenite to 2.6% was observed after the first grinding of a hardened cut sample. Additionally, an unexpectedly large decrease in the austenite content to 2.3% was found due to the final polishing. A second time applied successive grinding and polishing of all samples resulted in identical austenite content determined by CXMS of approx. 5%, which proved the applicability of the CXMS method. Generally, the result calls attention to the importance of preparation of metallurgical samples by grinding and polishing where the results can vary significantly on the level of surface processing.

Diagnosing Extrusion Process Based on Displacement Signal and Simple Decision Tree Classifier

The article presents an extensive analysis of the literature related to the diagnosis of the extrusion process and proposes a new, unique method. This method is based on the observation of the punch displacement signal in relation to the die, and then approximation of this signal using a polynomial. It is difficult to find in the literature even an attempt to solve the problem of diagnosing the extrusion process by means of a simple distance measurement. The dominant feature is the use of strain gauges, force sensors or even accelerometers. However, the authors managed to use the displacement signal, and it was considered a key element of the method presented in the article. The aim of the authors was to propose an effective method, simple to implement and not requiring high computing power, with the possibility of acting and making decisions in real time. At the input of the classifier, authors provided the determined polynomial coefficients and the SSE (Sum of Squared Errors) value. Based on the SSE values only, the decision tree algorithm performed anomaly detection with an accuracy of 98.36%. With regard to the duration of the experiment (single extrusion process), the decision was made after 0.44 s, which is on average 26.7% of the extrusion experiment duration. The article describes in detail the method and the results achieved.

A versatile method for dorsal-approach plantar plate repair using standard operative instruments

Background The plantar plate is an important static stabilizer of the lesser metatarsophalangeal joints, and disruptions of the plantar plate can lead to significant instability and lesser toe deformities. In recent years, direct plantar plate repair has been proposed. Although direct repair via a dorsal approach is attractive, a torn plantar plate is small and difficult to access using regular instruments in a restricted operative field. Methods In this report, a unique method for plantar plate repairs was used to repair various configurations of plantar plate tears with standard operative instruments that are available in most operating rooms. Results Using this method, 10 patients underwent plantar plate repairs, and the mean follow-up period was 24 (range, 14–38) months. The mean visual analog scale score for pain preoperatively was 4.1 (range, 0–6) and decreased to 0.6 (range, 0–3) at last follow-up. Postoperatively, the mean visual analog scale score for satisfaction was 9.6 (range, 8–10) and the mean American Orthopedic Foot and Ankle Society forefoot score was 88.8 (range, 75–100). Conclusions Our study proposes an inexpensive and versatile method for plantar plate repair via a dorsal approach that uses standard operative instruments. Trial registration ClinicalTrials.gov, NCT04949685. July 2, 2021 - Retrospectively registered, Level of clinical evidence 4

A Review of Chronological Evolution of Air Quality Indexing Systems (1966 To 2021)

Air quality index (AQI) also known as air pollution index (API) is the way of describing ambient air quality to assess the health risk associated with pollution. With the advent of time, there have been several air quality indexing systems starting from the first air Quality Index developed in 1966 by Marvin H. Green and various modifications have been made ever since to improve the accuracy of measurement. Such systems can assess the air quality by several factors like the concentration of different pollutants or by various empirically established formulas based on past experiences. In this review article, an effort has been made to chronologically evaluate the AQI system developed across the world from 1966 to 2021. Every indexing system has its own unique method for air quality determination and each method has its own merits and demerits. This pape rcovers various parameters, empirical relationships, standards, merits, and demerits, which in hind sight will help to develop an amalgamation of various indexing systems that can be used as a standard method for monitoring the quality of air. This paper also covers the AQI systems that prevail in India. A fuzzy logic system is very helpful in handling the uncertainty in air quality assessment. So, fuzzy-based air quality indexing systems developed from 2010 to 2017 have also been reviewed. The review of articles established that the results obtained through fuzzybased AQI aremore reliable than the other methods. Out of all the above describing methods, fuzzy synthetic evaluation-based AQI system and fuzzy air quality health index (FAQHI) are more powerful tools to describe the air quality. But till 2017, thereis no development of AQI systems based on fuzzy logic, considering PM2.5 as one of the pollutants. So, there is a need to develop the fuzzy-based AQI system considering PM2.5 as a pollutant with other air pollutants.

MANAGEMENT OF COTTON BUD INDUCED OTITIS EXTERNA BY UNIQUE METHOD

Objective: To compare the recovery of patients in both groups having acute otitis externa induced by cotton buds/various objects. One group by old method and second group by unique method. Study Design: Quasi-experimental study. Place and Duration of Study: Pakistan Naval Ship Shifa Karachi, from Jan to Dec 2020. Methodology: Non-probability convenience sampling technique was applied. Out of 50 cases were selected for group 1 management. Fifty cases were selected for group 2 management. A chi-square test was applied to compare the recovery of two groups of patients on the 14th day and 42nd day of follow-up. p-value was kept 0.05 as significant. Results: A total of 100 cases were treated in 2 groups. The gender distribution of the study was 54 females and 46 males. The mean age of the study population was 33.09 ± 12.93 years. p-value was calculated on the 14th day and 42nd days. A 2x2 table of 14th follow up day showed recovery by both groups with a p-value of 0.041 which is <0.05. This showed that group 2 management was statistically better than group 1 management. Conclusion: The second group was managed with eardrops containing Betamethasone and Neomycin. This management protocol is unique and better than conventional management as done in the first group.

A unique method for management of benign colonic masses: case report

Even though lipomas are most common non-epithelial tumors of the large intestine, they mostly present with non-specific symptoms. Intussusception is the most common morbidity related to such lesions and may present as intestinal obstruction. We present here a case of a young female who presented to gastroenterology department as a case of pain abdomen and nausea and a provisional diagnosis of subacute intestinal obstruction was kept. Contrast enhanced CT confirmed a diagnosis of intussusception due to an ascending colon mass? likely lipoma. The colonoscopy was done and biopsy was taken which was non-specific for malignancy. Patient, after taking due consent, was taken for surgery and laparoscopic assisted submucosal excision of lipoma was done and we will discuss the same. Endoscopic excision of lipomas has been reported but when failed, mostly segmental resection of the colon has been reported. To the best of our knowledge, this is the second reported case of laparoscopic assisted colotomy with submucosal excision of an intussuscepting colonic lipoma and first one in ascending colon.

Harnessing the Intrinsic Photochemistry of Isoxazoles for the Development of Chemoproteomic Crosslinking Methods

Photo-crosslinking is a powerful technique for identifying both coarse- and fine-grained information on protein binding by small molecules. However, the scope of useful functional groups remains limited, with most studies focusing on diazirine, aryl azide, or benzophenone-containing molecules. Here, we report a unique method for photo-crosslinking, employing the intrinsic photochemistry of the isoxazole, a common heterocycle in medicinal chemistry, to offer an alternative to existing strategies using more perturbing, extrinsic crosslinkers. In this initial report, this technique is applied both in vitro and ex vivo, used in a variety of common chemoproteomic workflows, and validated across multiple proteins, demonstrating the utility of isoxazole photo-crosslinking in a wide range of biologically relevant experiments.

The Phases of Hahnemann's Medical Practice

Using data from his casebooks, this study explores the medical practice of Hahnemann with a focus on his changing use of medicines and potency. This study also identifies several phases in his use of medicines that connect with his ongoing programme of new provings. This study also reveals that only when he had chanced upon the antipsoric medicines, he did stop changing his medicines. Similarly, data taken from the casebooks reveal changes in his use of potency and the development of his unique method of preparing medicines as he experimented with higher and higher potencies as his career progressed.