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Biomimetic retinas with a wide field of view and high resolution are in demand for neuroprosthetics and robot vision. Conventional neural prostheses are manufactured outside the application area and implanted as a complete device using invasive surgery. Here, a minimally invasive strategy based on in situ self-assembly of photovoltaic microdevices (PVMs) is presented. The photoelectricity transduced by PVMs upon visible light illumination reaches the intensity levels that could effectively activate the retinal ganglion cell layers. The geometry and multilayered architecture of the PVMs along with the tunability of their physical properties such as size and stiffness allow several routes for initiating a self-assembly process. The spatial distribution and packing density of the PVMs within the assembled device are modulated through concentration, liquid discharge speed, and coordinated self-assembly steps. Subsequent injection of a photocurable and transparent polymer facilitates tissue integration and reinforces the cohesion of the device. Taken together, the presented methodology introduces three unique features: minimally invasive implantation, personalized visual field and acuity, and a device geometry adaptable to retina topography., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

The concept of creating all-mechanical soft microrobotic systems has great potential to address outstanding challenges in biomedical applications, and introduce more sustainable and multifunctional products. To this end, magnetic fields and light have been extensively studied as potential energy sources. On the other hand, coupling the response of materials to pressure waves has been overlooked despite the abundant use of acoustics in nature and engineering solutions. In this study, we show that programmed commands can be contained on 3D nanoprinted polymer systems with the introduction of selectively excited air bubbles and rationally designed compliant mechanisms. A repertoire of micromechanical systems is engineered using experimentally validated computational models that consider the effects of primary and secondary pressure fields on entrapped air bubbles and the surrounding fluid. Coupling the dynamics of bubble oscillators reveals rich acoustofluidic interactions that can be programmed in space and time. We prescribe kinematics by harnessing the forces generated through these interactions to deform structural elements, which can be remotely reconfigured on demand with the incorporation of mechanical switches. These basic actuation and analog control modules will serve as the building blocks for the development of a novel class of micromechanical systems powered and programmed by acoustic signals.

The dynamics and connectivity of neural circuits continuously change on timescales ranging from milliseconds to an animal's lifetime. Therefore, to understand biological networks, minimally invasive methods are required to repeatedly record them in behaving animals. Here we describe a suite of devices that enable long-term optical recordings of the adult Drosophila melanogaster ventral nerve cord (VNC). These consist of transparent, numbered windows to replace thoracic exoskeleton, compliant implants to displace internal organs, a precision arm to assist implantation, and a hinged stage to repeatedly tether flies. To validate and illustrate our toolkit we (i) show minimal impact on animal behavior and survival, (ii) follow the degradation of chordotonal organ mechanosensory nerve terminals over weeks after leg amputation, and (iii) uncover waves of neural activity caffeine ingestion. Thus, our long-term imaging toolkit opens up the investigation of premotor and motor circuit adaptations in response to injury, drug ingestion, aging, learning, and disease., (© 2022. The Author(s).)

Malignant transformation and tumour progression are associated with cancer-cell softening. Yet how the biomechanics of cancer cells affects T-cell-mediated cytotoxicity and thus the outcomes of adoptive T-cell immunotherapies is unknown. Here we show that T-cell-mediated cancer-cell killing is hampered for cortically soft cancer cells, which have plasma membranes enriched in cholesterol, and that cancer-cell stiffening via cholesterol depletion augments T-cell cytotoxicity and enhances the efficacy of adoptive T-cell therapy against solid tumours in mice. We also show that the enhanced cytotoxicity against stiffened cancer cells is mediated by augmented T-cell forces arising from an increased accumulation of filamentous actin at the immunological synapse, and that cancer-cell stiffening has negligible influence on: T-cell-receptor signalling, production of cytolytic proteins such as granzyme B, secretion of interferon gamma and tumour necrosis factor alpha, and Fas-receptor-Fas-ligand interactions. Our findings reveal a mechanical immune checkpoint that could be targeted therapeutically to improve the effectiveness of cancer immunotherapies., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

A design, manufacturing, and control methodology is presented for the transduction of ultrasound into frequency-selective actuation of multibody hydrogel mechanical systems. The modular design of compliant mechanisms is compatible with direct laser writing and the multiple degrees of freedom actuation scheme does not require incorporation of any specific material such as air bubbles. These features pave the way for the development of active scaffolds and soft robotic microsystems from biomaterials with tailored performance and functionality. Finite element analysis and computational fluid dynamics are used to quantitatively predict the performance of acoustically powered hydrogels immersed in fluid and guide the design process. The outcome is the remotely controlled operation of a repertoire of untethered biomanipulation tools including monolithic compound micromachinery with multiple pumps connected to various functional devices. The potential of the presented technology for minimally invasive diagnosis and targeted therapy is demonstrated by a soft microrobot that can on-demand collect, encapsulate, and process microscopic samples., Competing Interests: The authors declare no conflict of interest., (© 2020 The Authors. Published by Wiley‐VCH GmbH.)

The appearance of DNA in the cytosol is perceived as a danger signal that stimulates potent immune responses through cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS). How cells regulate the activity of cGAS toward self-DNA and guard against potentially damaging autoinflammatory responses is a fundamental biological question. Here, we identify barrier-to-autointegration factor 1 (BAF) as a natural opponent of cGAS activity on genomic self-DNA. We show that BAF dynamically outcompetes cGAS for DNA binding, hence prohibiting the formation of DNA-cGAS complexes that are essential for enzymatic activity. Upon acute loss of nuclear membrane integrity, BAF is necessary to restrict cGAS activity on exposed DNA. Our observations reveal a safeguard mechanism, distinct from physical separation, by which cells protect themselves against aberrant immune responses toward genomic DNA., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

We present a methodology for building biologically inspired, soft microelectromechanical systems (MEMS) devices. Our strategy combines several advanced techniques including programmable colloidal self-assembly, light-harvesting with plasmonic nanotransducers, and in situ polymerization of compliant hydrogel mechanisms. We synthesize optomechanical microactuators using a template-assisted microfluidic approach in which gold nanorods coated with thermoresponsive poly(N-isopropylmethacrylamide) (pNIPMAM) polymer function as nanoscale building blocks. The resulting microactuators exhibit mechanical properties (4.8 ± 2.1 kPa stiffness) and performance metrics (relative stroke up to 0.3 and stress up to 10 kPa) that are comparable to that of bioengineered muscular constructs. Near-infrared (NIR) laser illumination provides effective spatiotemporal control over actuation (sub-micron spatial resolution at millisecond temporal resolution). Spatially modulated hydrogel photolithography guided by an experimentally validated finite element-based design methodology allows construction of compliant poly(ethylene glycol) diacrylate (PEGDA) mechanisms around the microactuators. We demonstrate the versatility of our approach by manufacturing a diverse array of microdevices including lever arms, continuum microrobots, and dexterous microgrippers. We present a microscale compression device that is developed for mechanical testing of three-dimensional biological samples such as spheroids under physiological conditions.

Acoustic actuation of bioinspired microswimmers is experimentally demonstrated. Microswimmers are fabricated in situ in a microchannel. Upon acoustic excitation, the flagellum of the microswimmer oscillates, which in turn generates linear or rotary movement depending on the swimmer design. The speed of these bioinspired microswimmers is tuned by adjusting the voltage amplitude applied to the acoustic transducer. Simple microfabrication and remote actuation are promising for biomedical applications.

We present an acoustofluidic micromixer which can perform rapid and homogeneous mixing of highly viscous fluids in the presence of an acoustic field. In this device, two high-viscosity polyethylene glycol (PEG) solutions were co-injected into a three-inlet PDMS microchannel with the center inlet containing a constant stream of nitrogen flow which forms bubbles in the device. When these bubbles were excited by an acoustic field generated via a piezoelectric transducer, the two solutions mixed homogenously due to the combination of acoustic streaming, droplet ejection, and bubble eruption effects. The mixing efficiency of this acoustofluidic device was evaluated using PEG-700 solutions which are ~106 times more viscous than deionized (DI) water. Our results indicate homogenous mixing of the PEG-700 solutions with a ~0.93 mixing index. The acoustofluidic micromixer is compact, inexpensive, easy to operate, and has the capacity to mix highly viscous fluids within 50 milliseconds.

A polydimethylsiloxane microchannel featuring sidewall sharp-edge structures and bare channels, and a piezoelement transducer is attached to a thin glass slide. When an external acoustic field is applied to the microchannel, the oscillation of the sharp-edge structures and the thin glass slide generate acoustic streaming flows which in turn rotate single cells and C. elegans in-plane and out-of-plane., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We have demonstrated in situ fabricated and acoustically actuated microrotors. A polymeric microrotor with predefined oscillating sharp-edge structures is fabricated in situ by applying a patterned UV light to polymerize a photocrosslinkable polyethylene glycol solution inside a microchannel around a polydimethylsiloxane axle. To actuate the microrotors by oscillating the sharp-edge structures, we employed piezoelectric transducers which generate tunable acoustic waves. The resulting acoustic streaming flows rotate the microrotors. The rotation rate is tuned by controlling the peak-to-peak voltage applied to the transducer. A 6-arm microrotor can exceed 1200 revolutions per minute. Our technique is an integration of single-step microfabrication, instant assembly around the axle, and easy acoustic actuation for various applications in microfluidics and microelectromechanical systems (MEMS).

Objective: Postoperative atrial fibrillation is a common complication after cardiac surgery, with an incidence as high as 20-50%. Increased age is associated with a significant increase in postoperative atrial fibrillation risk. This common complication is associated with higher morbidity and mortality rates. The aim of this study was to assess the efficacy of nebivolol in preventing atrial fibrillation following coronary artery bypass surgery in patients over 60 years of age., Methods: In this prospective randomized study, 200 patients who were candidates for elective coronary artery bypass surgery were divided into two groups. The first group was administered with nebivolol and the second group was administered with metoprolol. Treatment was initiated four days prior to surgery, and patients were monitored for atrial fibrillation until discharge. Forty-one patients received 50 mg metoprolol succinate daily, which was initiated minimum 4 days before surgery., Results: Demographic data were similar in both groups. The incidence of postoperative atrial fibrillation in both groups was similar, with no significant difference being identified [n=20 (20%); n=18 (18%), P=0.718; respectively]. There were not any mortality at both groups during study. Inotropic agent requirement at ICU was similar for both groups [n=12 (12%), n=18 (18%), P=0.32]., Conclusion: We compared the effectiveness of nebivolol and metoprolol in decreasing the incidence of postoperative atrial fibrillation, and determined that nebivolol was as effective as metoprolol in preventing postoperative atrial fibrillation at patients. Nebivolol may be the drug of choice due to its effects, especially after elective coronary artery bypass surgery.

Background: This study was conducted to investigate how brief pretreatments with 4 different vasodilators applied topically at normal body temperature affect blood flow in the internal mammary artery., Methods: One hundred patients who had an internal mammary artery mobilized as a pedicle for coronary artery bypass grafting were randomly assigned to one of 5 groups of equal size (20 subjects in each). Each group of pedicles was treated with a different topical solution: normal saline (control), nitroglycerin, diltiazem, papaverine, or adenosine. Internal mammary artery flow and hemodynamic measurements were recorded immediately after harvesting and after 5 minutes of immersion in a tube filled with test solution (50 mL at 37 degrees C). Results for each study variable were compared within and between groups, and posttreatment-to-pretreatment ratios were also calculated and compared., Results: All 4 vasodilator groups showed a significant increase in internal mammary artery flow rate from pretreatment to posttreatment, whereas the saline group did not. There were no significant differences among the 5 groups' pretreatment flow rates (P = .526) or posttreatment flow rates (P = .194). The mean ratio values (posttreatment-to-pretreatment) for flow rate were 1.08 +/- 0.17 in the saline group, 1.74 +/- 0.17 with nitroglycerin, 1.77 +/- 0.49 with diltiazem, 1.82 +/- 0.59 with papaverine, and 1.57 +/- 0.54 with adenosine. Post hoc analysis revealed that the mean ratio values for flow rate in the 4 vasodilator groups were significantly higher than the corresponding ratio in the saline group., Conclusions: Brief treatment of the internal mammary artery with topical vasodilators at normal body temperature significantly increases blood flow in this vessel. The data from this study are particularly valuable in relation to off-pump surgery, in which this vessel is usually anastomosed soon after it is harvested.

We compared chromosome 8 and 11 aneuploidies on bladder biopsy tumor tissues and bladder washing samples of transitional cell carcinoma (TCC) and their relationship to tumor malignancy. Interphase fluorescence in situ hybridization (FISH) was applied to nuclei of washing material and biopsy samples of 17 patients with TCC. Incidence of cells having aneuploidy was clearly nonrandom from patient to patient. There was no significant difference in the incidence of aneuploid frequency for chromosomes 8 and 11 between biopsies of bladder tumors and bladder washing samples (P > 0.05). For chromosome 8, incidence of disomic cells (having two signals) in grade III tumors was significantly lower than in grade II tumors of both washing samples (P = 0.004) and biopsy materials (P = 0.005), indicating a high frequency of aneuploidy. The incidence of nuclei with four or more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors in washing samples (P = 0.031 and 0.003, respectively). Similarly, in biopsy material, the incidence of nuclei with more than four signals of chromosome 8 was significantly higher in grade III tumors than in grade II tumors (P = 0.004). For chromosome 11, in both washing samples and biopsy materials, the incidence of disomic cells (having two signals) in grade III tumors was significantly lower than that detected in grade II tumors (P = 0.031 and 0.014, respectively), indicating a high frequency of aneuploidy. In biopsy materials, the incidence of nuclei with three or four signals was significantly higher than that in grade II tumors (P = 0.014 and 0.012, respectively). These findings suggest that FISH analysis of bladder washing samples can be effectively detected as genetic changes of bladder tumors. It might predict genetic progression of these tumors, which might be related to tumor stage, because higher stages of tumors showed a higher incidence of aneuploidies of chromosomes 8 and 11.

Structural chromosomal abnormalities in gonadal tissue represent an important category of parentally transmittable unbalanced chromosomal abnormalities to the offspring. A child with multiple anomalies was sent for cytogenetic analysis, and his karyotype was 46,XY,der(17)t(15;17)(q21; q25). This abnormality was transferred from his grandfather to his father and to the proband. In this family, 5 persons (1 female and 4 male) are the carriers of this abnormality. In this study, fluorescence in situ hybridization (FISH) on sperm nuclei of 4 male carriers was studied to determine the distribution of segregation patterns of the balanced translocation 15q;17q. The segregation results showed that the segregation products in the third carrier (the grandfather) were different, but they were not statistically significant. The segregation patterns in the other carriers were similar. Overall, 50.3% of the sperm nuclei (mean value for 4 carriers) analyzed were the result of alternate segregation; 36.9%, of adjacent I segregation; 9.0%, of adjacent II segregation; and 2.4%, of 3:1 segregation; the remaining 1.3% could be diploid sperm nuclei or of 4:0 segregation. Multicolor FISH analysis appears to be a rapid and reliable method for the direct analysis of segregation patterns in sperm nuclei of carriers of balanced reciprocal translocation, and it also provides interesting information for determining the possible risks for the offspring.

We have used the single and dual color fluorescence in situ hybridization (FISH) technique combined with a new detection system, tyramide signal amplification (TSA), by using the multiple endocrine neoplasm type 1 (MEN1) gene and chromosome 11 specific alpha satellite DNA probes for the study of the allelic deletion of the MEN1 gene. The MEN1 gene is a new tumor suppressor gene and has been recently cloned on chromosome 11q13. FISH combined with the TSA detection system was performed on bone marrow interphase nuclei of 22 patients with acute myeloid leukemia (AML). The FISH-TSA analysis revealed the mono allelic deletion of the MEN1 gene in 4 out of 22 patients (18.18%), 2 of 9 AML-M2 patients (22.2%), 1 of 6 AML-M4 patients (16.6%), and 1 of 4 AML-M5 patients (25.0%). Our study indicates that allelic deletion of the MEN1 gene is not a major cause or a primary event in tumorigenesis of AML, although the long arm (q13 region) of chromosome 11 involves a chromosomal rearrangement in AML., (Copyright 2002 Wiley-Liss, Inc.)