Self-Amputating and Interfusing Machines.

Biological organisms exhibit phenomenal adaptation through morphology-shifting mechanisms including self-amputation, regeneration, and collective behavior. For example, reptiles, crustaceans, and insects amputate their own appendages in response to threats. Temporary fusion between individuals enables collective behaviors, such as in ants that temporarily fuse to build bridges. The concept of morphological editing often involves the addition and subtraction of mass and can be linked to modular robotics, wherein synthetic body morphology may be revised by rearranging parts. This work describes a reversible cohesive interface made of thermoplastic elastomer that allows for strong attachment and easy detachment of distributed soft robot modules without direct human handling. The reversible joint boasts a modulus similar to materials commonly used in soft robotics, and can thus be distributed throughout soft robot bodies without introducing mechanical incongruities. To demonstrate utility, the reversible joint is implemented in two embodiments: a soft quadruped robot that self-amputates a limb when stuck, and a cluster of three soft-crawling robots that fuse to cross a land gap. This work points toward future robots capable of radical shape-shifting via changes in mass through autotomy and interfusion, as well as highlights the crucial role that interfacial stiffness change plays in autotomizable biological and artificial systems.

Reprogrammable soft actuation and shape-shifting via tensile jamming.

The emerging generation of robots composed of soft materials strives to match biological motor adaptation skills via shape-shifting. Soft robots often harness volumetric expansion directed by strain limiters to deform in complex ways. Traditionally, strain limiters have been inert materials embedded within a system to prescribe a single deformation. Under changing task demands, a fixed deformation mode limits adaptability. Recent technologies for on-demand reprogrammable deformation of soft bodies, including thermally activated variable stiffness materials and jamming systems, presently suffer from long actuation times or introduce unwanted bending stiffness. We present fibers that switch tensile stiffness via jamming of segmented elastic fibrils. When jammed, tensile stiffness increases more than 20× in less than 0.1 s, but bending stiffness increases only 2×. When adhered to an inflating body, jamming fibers locally limit surface tensile strains, unlocking myriad programmable deformations. The proposed jamming technology is scalable, enabling adaptive behaviors in emerging robotic materials that interact with unstructured environments.

Hope and doubt in the promise of neuroimaging: The case of autism spectrum disorder.

Although neuroimaging is currently not a component of the diagnostic process for autism spectrum disorders, some scientists hail these technologies for their promise to one day replace behaviorally based psychiatric diagnostic techniques. This article examines how psychiatrists understand the potential use of neuroimaging technologies within the context of clinical practice. Drawing on 10 semi-structured interviews with child and adolescent psychiatrists, I describe the hope and doubt that comprise their discourse of ambivalence. This analysis demonstrates that the uses and meanings of neuroimaging technologies are rearticulated in ongoing debates in the field of psychiatry regarding the role of the biopsychiatric model in the diagnosis and treatment of mental illness. This study highlights issues surrounding the perceived biopsychiatric focus of neuroimaging technologies within clinical practice, concerns regarding misdirected research attention, and the ways in which understandings of future utility mediate perceptions of technological utility.

Primary clear cell carcinoma of the rete testis: 1st report.

Primary tumours of the rete testis, either benign or malignant, are very rare. Such lesions require careful scrutiny including immunohistochemical analysis to exclude malignant lesions such as mesothelioma or papillary serous carcinoma. To the best of our knowledge this is the first report of a primary clear cell carcinoma of the rete testis. The possibility of a primary renal cell carcinoma or other primary site with metastatic spread to rete testis was excluded by thorough clinical and radiological work-up.

Application of quantitative PCR for the detection of microorganisms in water.

The occurrence of microorganisms in water due to contamination is a health risk and control thereof is a necessity. Conventional detection methods may be misleading and do not provide rapid results allowing for immediate action. The quantitative polymerase chain reaction (qPCR) method has proven to be an effective tool to detect and quantify microorganisms in water within a few hours. Quantitative PCR assays have recently been developed for the detection of specific adeno- and polyomaviruses, bacteria and protozoa in different water sources. The technique is highly sensitive and able to detect low numbers of microorganisms. Quantitative PCR can be applied for microbial source tracking in water sources, to determine the efficiency of water and wastewater treatment plants and act as a tool for risk assessment. Different qPCR assays exist depending on whether an internal control is used or whether measurements are taken at the end of the PCR reaction (end-point qPCR) or in the exponential phase (real-time qPCR). Fluorescent probes are used in the PCR reaction to hybridise within the target sequence to generate a signal and, together with specialised systems, quantify the amount of PCR product. Quantitative reverse transcription polymerase chain reaction (q-RT-PCR) is a more sensitive technique that detects low copy number RNA and can be applied to detect, e.g. enteric viruses and viable microorganisms in water, and measure specific gene expression. There is, however, a need to standardise qPCR protocols if this technique is to be used as an analytical diagnostic tool for routine monitoring. This review focuses on the application of qPCR in the detection of microorganisms in water.

Estimation of clinically significant prostate volumes by digital rectal examination: a comparative prospective study.

INTRODUCTION: Reliable quantification of prostate volume is important to correctly select patients with benign prostatic hyperplasia (BPH) most likely to benefit from medical therapy [e.g. 5 alpha-reductase inhibitors (5-ARIs)] and in selecting appropriate surgical approach. We aim to determine the reliability of digital rectal examination (DRE) in estimation of prostate volume which may be helpful in patient selection for 5-ARIs therapy. MATERIALS AND METHODS: Patients requiring transrectal ultrasound (TRUS) guided prostate biopsy were recruited in this prospective study. DRE was performed twice for each patient. Clinicians categorized prostate volume on DRE into small, medium and large, and estimated prostate volume. Volume estimated by DRE at the first examination was intentionally unavailable at second DRE. TRUS volumes were measured using 2101 Falcon ultrasound machine. RESULTS: Comparative analysis of prostate volume (n = 248) by DRE and TRUS was performed. There was no significant difference between DRE-estimated prostate volume at the first and second examinations (p = 0.8). DRE-estimated volumes for prostates categorized as small, medium or large were underestimated in 59%, 58% and 53% of patients respectively. However, for clinical relevant volumes (> 30 cc), 94.5% patients were accurately estimated on DRE. CONCLUSIONS: We have shown that DRE had positive predictive value of 94% in identifying prostate above 30 cc. Hence, when considering treatment with 5-ARIs, DRE may be sufficient to identify suitable patients for 5-ARIs therapy. However, for prostate volumes between 25 cc-30 cc and above 80 cc, TRUS may be required.

The potential of nanofibers and nanobiocides in water purification.

Electrospun nanofibers and nanobiocides show potential in the improvement of water filtration membranes. Biofouling of membranes caused by the bacterial load in water reduces the quality of drinking water and has become a major problem. Several studies showed inhibition of these bacteria after exposure to nanofibers with functionalized surfaces. Nanobiocides such as metal nanoparticles and engineered nanomaterials are successfully incorporated into nanofibers showing high antimicrobial activity and stability in water. Research on the applications of nanofibers and nanobiocides in water purification, the fabrication thereof and recently published patents are reviewed in this article.

Restraint stress and exogenous corticosterone differentially alter sensitivity to the sedative-hypnotic effects of ethanol in inbred long-sleep and inbred short-sleep mice.

Decreased sensitivity to ethanol is a genetically mediated trait implicated in susceptibility to developing alcoholism. Here, we explore genotype by environment differences in ethanol sensitivity. The relationship between acute- and repeated-restraint stress, corticosterone (CORT) levels, and sensitivity to sedative-hypnotic properties of ethanol was explored using inbred long-sleep (ILS) and inbred short-sleep (ISS) mice. In ILS mice, acute restraint decreased ethanol sensitivity at a 4.1g/kg dose, as measured by a decrease in the duration of loss of the righting reflex (LORE) and an increase in blood ethanol concentration at regain of the righting response (BECRR). Repeated restraint also decreased LORE duration, but had no effect on BECRR. In the ISS mice, there was no effect of acute restraint on either LORE duration or BECRR. However, repeated restraint increased ethanol sensitivity at a 4.1g/kg dose; with an increase in LORE duration, but a decrease in BECRR. Differences in hypothalamic-pituitary-adrenal (HPA) axis responsiveness to restraint stress (as measured by plasma CORT) were also examined between genotypes. ILS mice displayed habituation to repeated restraint, whereas ISS mice did not. Lastly, the effect of enhanced CORT levels independent of psychological stress was examined for its effects on the sedative-hypnotic effects of ethanol. There were no effects of CORT pretreatment on LORE duration or BECRR in ILS mice compared to saline- or noninjected littermates. In contrast, ISS mice injected with CORT showed a decreased duration of LORE, but no effects on BECRR. These findings suggest that in addition to genetic susceptibility, environmental factors (e.g., restraint stress, exogenous CORT administration) also influence sensitivity to the sedative effects of ethanol through alteration of central nervous system sensitivity and pharmacokinetic parameters, and do so in a genotype-dependent manner.