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Organoids are three-dimensional cell clusters derived from stem cells and closely resemble the physiological characteristics of human tissues. As the next-generation biological model, organoids provide new opportunities for drug discovery, disease modeling, and personalized medicine. To fully harness the potential of organoids, real-time monitoring of biological states and functional evaluation of organoids are crucial. This review highlights recent advances in real-time, in situ biosensing technologies, including microelectrode arrays for electrophysiological recordings, chemical sensors for biochemical detection, and strain sensors for monitoring mechanical properties. While the development of miniature sensors for non-invasive, long-term, and real-time monitoring of organoids is in the early stage, these sensors are an essential part of organoid technology which would provide new insights into human developmental biology, pathophysiology, and drug discovery. After reviewing the seminal works on the microfabricated sensors for organoids, we also provide an outlook of the field including a discussion on the remaining challenges and future directions with a focus on integration of multiple sensors to facilitate organoid research and applications. [ABSTRACT FROM AUTHOR]

Purpose: Long-term patient satisfaction may influence patients' perspectives of the quality of care and their relationship with their providers. This is a follow up to a comparative effectiveness study investigating oral to intravenous sedation (OIV study). The OIV study found that oral sedation was noninferior in patient satisfaction to standard intravenous (IV) sedation for anterior segment and vitreoretinal surgeries. This study aims to determine if patient satisfaction with oral sedation remained noninferior long term. Patients and Methods: Patients were re-interviewed using the same satisfaction survey given during the OIV study. Statistical analysis involved t-tests for noninferiority of the long-term mean satisfaction score of oral and IV sedation. We also compared the original mean satisfaction score and the follow-up mean satisfaction score for each type of sedation and for both groups combined. Results: Participants were interviewed at a median of 1225.5 days (range 754– 1675 days) from their surgery. The original mean satisfaction score was 5.26 ± 0.79 for the oral treatment group (n = 52) and 5.27 ± 0.64 for the intravenous treatment group (n = 46), demonstrating noninferiority with a difference in mean satisfaction score of 0.015 (p < 0.0001). The follow-up mean satisfaction score was 5.23 ± 0.90 for oral sedation and 5.60 ± 0.61 for IV sedation, with a difference in the mean satisfaction score of 0.371 (p = 0.2071). Satisfaction scores did not differ between the original mean satisfaction score and the follow-up mean satisfaction score for the oral treatment group alone (p = 0.8367), but scores in the intravenous treatment group increased longitudinally (p = 0.0004). Conclusion: In this study, long-term patient satisfaction with oral sedation was not noninferior to satisfaction with IV sedation, unlike our findings with short-term patient satisfaction in our original study. Patient satisfaction also remained unchanged over time for the oral treatment group, but patients in the intravenous treatment group reported higher long-term satisfaction with their anesthesia experience compared to the immediate post-operative period. [ABSTRACT FROM AUTHOR]

Continuous monitoring of bio/physiological signals will play an essential role in personalized, patient‐centric medicine in the future healthcare industry. One of the challenges involves providing a sustainable, energy‐efficient operation for long‐term monitoring devices. The current technology based on power sources requires periodic replacement. Here, a hybrid film composed of a layer of piezoelectric nanowire (PVDFHFP) and a layer of microgel (pNIPAM‐APBA) is presented that continuously monitors glucose, does not rely on enzymes, is self‐charging, and decouples changes in read‐out signals due to glucose detection from the force is applied to activate self‐charging. By characterizing self‐charging/discharging properties, the operation and sensing mechanism for the nanowire/microgel hybrid film are proposed. A reasonable sensitivity of 70 mV mm−1 with a high linearity value of R2 = 0.9956 is observed. This work demonstrates the potential for use in a self‐charging wearable platform that enables continuous monitoring of bio/physiological signals. [ABSTRACT FROM AUTHOR]

Detection of neurotransmitters for in vitro analysis systems is an essential component in evaluating the integrity and viability of in vitro models of neurodegenerative disorders and the cytotoxicity of drug candidates. Currently, electrochemical analysis such as cyclic voltammetry (CV) is the most widely used method for the detection of neurotransmitters. However, while most in vitro analysis systems are based on optical imaging, electrochemical sensors are non‐transparent and hinder in situ simultaneous cell monitoring. In this work, a highly sensitive miniaturized electrochemical sensor that is also transparent is proposed, which enables simultaneous dopamine detection and in vitro optical assays. The microfabrication process and nanosphere lithography are utilized to fabricate a transparent working electrode. The transparent electrode is functionalized with the overoxidized polypyrrole/sodium dodecyl sulfate‐modified carbon nanotube (OPPy/SDS‐CNT). The detection of DA is successfully demonstrated using the miniaturized transparent sensor. In addition, the PC‐12 cell is cultured in the sensor‐integrated chamber and the cell viability is confirmed on the sensor over 3 days. The proposed miniature transparent sensor is a great candidate for next‐generational multi‐modal in vitro analysis systems. [ABSTRACT FROM AUTHOR]

Monitoring both individual neuronal spikes and neurotransmitters released from a specific brain region plays a significant role in understanding neuronal circuits and brain functionalities. While polymer neural probe offers distinctive advantages of flexibility, optical transparency, and biocompatibility, achieving high‐density recording with multifunctionalities and multimodality is still a challenge due to limited microfabrication techniques. Here, a multimodal polymer neural probe array based on a dual‐side fabrication process with the potential for high‐density neural recording and electrochemical neurotransmitter detection is presented. The developed dual‐side fabrication allows the placement of a larger number of microelectrodes and multimodal sensors without increasing the probe dimension by utilizing both sides of the shank. Using the dual‐side fabrication, a dual‐sided SU‐8 neural probe array is fabricated which consists of an array of gold and platinum microelectrodes and a micron‐scale three‐electrode system. Moreover, the design space of the micron‐scale three‐electrode systems on the dual‐side neural probe is explored. Through successful in vivo neural spike recording and dopamine (DA) measurements in a brain phantom using the fabricated dual‐side neural probe, it is confirmed that the dual‐sided microfabrication is a reliable and viable solution. [ABSTRACT FROM AUTHOR]

Transcranial focused ultrasound stimulation (tFUS) is an effective noninvasive treatment modality for brain disorders with high clinical potential. However, the therapeutic effects of ultrasound neuromodulation are not widely explored due to limitations in preclinical systems. The current preclinical studies are head‐fixed, anesthesia‐dependent, and acute, limiting clinical translatability. Here, this work reports a general‐purpose ultrasound neuromodulation system for chronic, closed‐loop preclinical studies in freely behaving rodents. This work uses microelectromechanical systems (MEMS) technology to design and fabricate a small and lightweight transducer capable of artifact‐free stimulation and simultaneous neural recording. Using the general‐purpose system, it can be observed that state‐dependent ultrasound neuromodulation of the prefrontal cortex increases rapid eye movement (REM) sleep and protects spatial working memory to REM sleep deprivation. The system will allow explorative studies in brain disease therapeutics and neuromodulation using ultrasound stimulation for widespread clinical adoption. [ABSTRACT FROM AUTHOR]

An IC flip-chip bonded to a 16 * 16-element capacitive micromachined ultrasonic transducer (CMUT) array is described for 3-D ultrasonic imaging. The IC flip-chip bonded to a CMUT array has shown that the IC can produce steered and focused ultrasound beams and the 2-D and 3-D images of a wire phantom and 2-D orthogonal cross-sectional images of a latex heart phantom are presented.

An acoustic matching layer is an essential component of an ultrasound transducer to achieve maximum ultrasound transmission efficiency. Here, we develop a flexible printed circuit board (FPCB) with a composite structure consisting of multiple polyimide and copper layers and demonstrate it as a novel acoustic matching layer. With a flexible substrate and robust ACF bonding, the FPCB not only serves as an acoustic matching layer between piezoelectric elements and the surrounding medium but also as a ground for the electrical connection between the transducer array elements and the folded substrate. A 1D linear ultrasound transducer array with the FPCB matching layer exhibits larger output pressure, wider -3dB bandwidth, and higher ultrasound beam intensity compared to that of an ultrasound transducer array with the alumina/epoxy matching layer, which is one of the most commonly applied composite matching layers. The enhanced transmission performance verifies that the proposed FPCB is an excellent matching layer for 1D linear ultrasound transducer arrays. [ABSTRACT FROM AUTHOR]

Purpose: To determine whether oral sedation is as safe and effective as IV sedation for ophthalmic surgeries other than cataract surgery, we tested whether patient satisfaction with oral triazolam was non-inferior to IV midazolam for cornea and glaucoma surgeries. Patients and Methods: Seventy-five cornea and 49 glaucoma surgery patients 18 years and older at Boston Medical Center (Boston, MA) were randomized within each study group (cornea or glaucoma) to receive oral triazolam + IV placebo, or oral placebo + IV midazolam before surgery in a double-masked fashion. Supplemental IV anesthesia was administered as needed during surgery. The primary outcome measure was patient satisfaction with anesthesia, compared between oral and IV sedation groups via t-test for non-inferiority, based on 70 cornea and 43 glaucoma subjects completing the study. Secondary outcome measures included surgeon and anesthesia provider satisfaction with anesthesia, rate of supplemental IV anesthesia, and incidence of adverse events and surgical complications. Results: Using an a priori non-inferiority margin of 0.5, initial oral sedation was non-inferior to initial IV sedation in cornea (n=70, p< 0.001) and glaucoma (n=43, p=0.017) groups, even after excluding subjects administered supplemental IV anesthesia. There were no significant differences in anesthesia provider or surgeon satisfaction, intra-operative complications, adverse events, or supplemental anesthesia between groups, except for higher anesthesia provider satisfaction with oral sedation in an Ahmed or Baerveldt implant ± cataract surgery sub-group (p=0.04). Subjects receiving supplemental anesthesia included 6 oral (18.2%) and 5 IV (13.5%) in the cornea group (p=0.59), and 7 oral (29.2%) and 6 IV (31.6%) in the glaucoma group (p=0.50). Conclusion: Our results suggest that an initial dose of oral triazolam is equivalent to IV midazolam for non-cataract anterior segment surgeries. However, there was a relatively high need for supplemental IV anesthesia during some surgery types, particularly with glaucoma tube shunt implantation. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate corneal endothelial cell density (ECD) and morphology between normal tension glaucoma (NTG) and controls. A cross-sectional, single center study of 24 NTG and 26 age-matched healthy eyes were included. ECD, mean cell size (MCA) and coefficient of variance (CV) were analyzed, controlling for age and number and duration of concurrent glaucoma medications. NTG subjects had significantly lower ECD (2307 ± 514.7 vs. 2558 ± 278.5, p = 0.044) and larger MCA (458.3 ± 94.8 vs. 386.7 ± 57.3, p = 0.004), but no difference in CV compared to healthy subjects. NTG subjects stratified by number of glaucoma medications showed significant differences in ECD (p = 0.024) and MCA (p = 0.021), but no difference in CV. There were no significant differences in ECD, MCA or CV between subjects stratified by duration of glaucoma medication usage. After age-adjusting, there was no dose-dependent relationship between mean ECD or MCA and number of glaucoma medications. Post hoc analysis demonstrated only NTG subjects on three or more glaucoma medications had statistically significant differences in ECD (p = 0.032) and MCA (p = 0.037) compared to NTG subjects on two glaucoma medications. This study suggests that NTG is associated with lower corneal endothelial cell density and mean cell size. [ABSTRACT FROM AUTHOR]

Purpose: This secondary analysis of a clinical trial that measured surgeon, anesthesiologist, and patient satisfaction following ophthalmic surgery under monitored anesthesia care (MAC) with a benzodiazepine investigates the degree of association between patient satisfaction with anesthesia compared to surgeon and anesthesiologist satisfaction with anesthesia. Patients and Methods: Data from analogous 6-point surgeon satisfaction surveys and anesthesiologist satisfaction surveys were compared to data from a 6-point validated patient satisfaction survey collected from a clinical trial investigating satisfaction with different forms of benzodiazepine for patients undergoing cataract, retina, cornea, or glaucoma surgery. Relationships between measures were analyzed using Pearson's correlation coefficient, with further subgroup analysis based on language groups and single-question measures of satisfaction. Results: A total of 283 ophthalmic surgical cases were analyzed. Mean surgeon satisfaction was 5.27 (range, 1.33– 6.00), mean anesthesiologist satisfaction was 5.12 (range, 1.17– 6.00), and mean patient satisfaction was 5.28 (range, 2.58– 6.00). The correlation between surgeon and patient satisfaction was 0.333 (p = 9.06e-9), while the correlation between anesthesiologist and patient satisfaction was 0.319 (p = 4.28e-8). There was no difference between English and non-English speaking patients in correlation between surgeon and patient satisfaction (p = 0.08) and anesthesiologist and patient satisfaction (p = 0.47). Conclusion: The data demonstrate a low level of association between patient satisfaction with anesthesia and provider satisfaction, even when patient language is taken into consideration. This suggests that providers are poor predictors of patient satisfaction with anesthesia and are unreliable judges of patient comfort perioperatively. [ABSTRACT FROM AUTHOR]

With the rapid increase in the use of optogenetics to investigate the nervous system, there is a high demand for a neural interface that enables 2D mapping of electrophysiological neural signals with high precision during simultaneous light stimulation. Here, a gold nanonetwork (Au NN)‐based transparent neural electrocorticogram (ECoG) monitoring system is proposed as implantable neural electronics. The neural interface enables accurate 2D mapping of ECoG neural signals without any photoelectric artifact during light stimulation. By using the Au NN, not only the transmittance of the microelectrodes is increased by 81% but also a low electrochemical impedance of 33.9 kΩ at 1 kHz with improved mechanical stability is achieved. It is demonstrated that the transparent microelectrode array records multichannel in vivo neural activities with no photoelectric artifact and a high signal‐to‐noise ratio. Propagation of neural dynamics of optically driven neural activities is also clearly visualized using the 2D Au NN microelectrode array. This transparent, flexible ECoG microelectrode array is a promising candidate for next‐generation in vitro and in vivo neural interface for 2D mapping of neural dynamics. [ABSTRACT FROM AUTHOR]

Development of polymeric memristors is of great interest for wearable and implantable applications because of its flexibility and transparency. One of distinguished polymeric memristor materials is silk fibroin, which is a biodegradable protein extracted from Bombyx mori cocoons. However, fibroin memristors demonstrated earlier show low memory cell density (<100 cells mm−2). In this paper, silk fibroin memristors with cell density 25 times higher than that of the previously reported silk fibroin memristors by utilizing wafer‐scale UV photolithography are reported. Unlike shadow masking technique adopted in the previous researches, UV photolithography allows single‐micrometer‐scale alignment between layers to obtain a much denser structure. Memristive characteristics of the silk fibroin memristors are studied under different values of compliance current during SET process with different thickness of silk fibroin films. The ON/OFF ratio of the fabricated memristors is maintained over 1000 s of measurement, and remains the same during bending over a cylinder with a radius of curvature of 1.3 mm. It is shown that silk fibroin remains biocompatible and biodegradable after undergoing the fabrication process. Demonstrated transparency and lightweight characteristics are desirable for electronic components for wearable and implantable systems. [ABSTRACT FROM AUTHOR]

Abstract Background Current transcranial ultrasound stimulation for small animal in vivo experiment is limited to acute stimulation under anesthesia in stereotaxic fixation due to bulky and heavy curved transducers. Methods We developed a miniaturized ultrasound ring array transducer which is capable of invoking motor responses through neuromodulation of freely-moving awake mice. Results: The developed transducer is a 32-element, 183-kHz ring array with a weight of 0.035 g (with PCB: 0.73 g), a diameter of 8.1 mm, a focal length of 2.3 mm, and lateral resolution of 2.75 mm. By developing an affixation scheme suitable for freely-moving animals, the transducer was successfully coupled to the mouse brain and induced motor responses in both affixed and awake states. Conclusion Ultrasound neuromodulation of a freely-moving animal is now possible using the developed lightweight and compact system to conduct a versatile set of in vivo experiments. [ABSTRACT FROM AUTHOR]

Abstract: With the increasing interest and demand for epidermal electronics, a strong interface between a sensor and a biological surface is essential, yet achieving such interface is still a challenge. Here, a calcium (Ca)‐modified biocompatible silk fibroin as a strong adhesive for epidermal electronics is proposed and the physical principles behind its interfacial and adhesive properties are reported. A strong adhesive characteristic (>800 N m−1) is observed because of the increase in both viscoelastic property and mechanical interlocking through the incorporation of Ca ions. Furthermore, additional key characteristics of the Ca‐modified silk: reusability, stretchability, biocompatibility, and conductivity, are reported. These characteristics enable a wide range of applications as demonstrated in four epidermal electronic systems: capacitive touch sensor, resistive strain sensor, hydrogel‐based drug delivery, and electrocardiogram monitoring sensor. As a reusable, biocompatible, conductive, and strong adhesive with water‐degradability, the Ca‐modified silk adhesive is a promising candidate for the next‐generation adhesive for epidermal biomedical sensors. [ABSTRACT FROM AUTHOR]

Novel drug delivery systems based on microtechnology have advanced tremendously, but yet face some technological and societal hurdles to fully achieve their potential. The novel drug delivery systems aim to deliver drugs in a spatiotemporal- and dosage-controlled manner with a goal to address the unmet medical needs from oral delivery and hypodermic injection. The unmet needs include effective delivery of new types of drug candidates that are otherwise insoluble and unstable, targeted delivery to areas protected by barriers ( e . g . brain and posterior eye segment), localized delivery of potent drugs, and improved patient compliance. After scrutinizing the design considerations and challenges associated with delivery to areas that cannot be efficiently targeted through standard drug delivery ( e . g . brain, posterior eye segment, and gastrointestinal tract), this review provides a summary of recent advances that addressed these challenges and summarizes yet unresolved problems in each target area. The opportunities for innovation in devising the novel drug delivery systems are still high; with integration of advanced microtechnology, advanced fabrication of biomaterials, and biotechnology, the novel drug delivery is poised to be a promising alternative to the oral administration and hypodermic injection for a large spectrum of drug candidates. [ABSTRACT FROM AUTHOR]

Multi-functional neural probes are promising platforms to conduct efficient and effective in-depth studies of brain by recording neural signals as well as modulating the signals with various stimuli. Here we present a neural probe with an embedded microfluidic channel (chemtrode) with multi-drug delivery capability suitable for small animal experiments. We integrated a staggered herringbone mixer (SHM) in a 3-inlet microfluidic chip directly into our chemtrode. This chip, which also serves as a compact interface for the chemtrode, allows for efficient delivery of small volumes of multiple or concentration-modulated drugs via chaotic mixing. We demonstrated the successful infusion of combinatorial inputs of three chemicals with a low flow rate (170 nl min−1). By sequentially delivering red, green, and blue inks from each inlet and conducting visual inspections at the tip of the chemtrode, we measured a short residence time of 14 s which corresponds to a small swept volume of 66 nl. Finally, we demonstrated the potential of our proposed chemtrode as an enabling tool through extensive in vivo mice experiments. Through simultaneous infusions of a chemical (pilocarpine or tetrodotoxin (TTX) at inlet 1), a buffer solution (saline at inlet 2), and 4′,6-diamidino-2-phenylindole (DAPI at inlet 3) locally into a mouse brain, we not only modulated the neural activities by varying the concentration of the chemical but also locally stained the cells at our target region (CA1 in hippocampus). More specifically, infusion of pilocarpine with a higher concentration resulted in an increase in neural activities while infusion of TTX with a higher concentration resulted in a distinctive reduction. For each chemical, we acquired multiple sets of data using only one mouse through a single implantation of the chemtrode. Our proposed chemtrode offers 1) multiplexed delivery of three drugs through a compact packaging with a small swept volume and 2) simultaneous recording to monitor near real-time effects on neural signals, which allows for more versatile in vivo experiments with a minimum number of animals to be sacrificed. [ABSTRACT FROM AUTHOR]

Multi-functional neural probes integrated with various stimulation modalities are becoming essential tools in neuroscience to study the brain more effectively. In this paper, we present a new multi-functional neural probe that allows chemical stimulation through drug delivery and simultaneous recording of individual neuron signals through a microelectrode array. By embedding microchannels in silicon using a proposed glass reflow process, we successfully fabricated 40 μm thick silicon neural probes suitable for small animal experiments. The electrochemical impedance spectroscopy confirms that impedance of iridium microelectrodes is low enough (＜1 MΩ at 1 kHz) to measure neural signals. Flow rate characterization in a 0.9% w/v agarose gel shows the capability to deliver a small volume of drugs (＜1 μl) at a controlled flow rate. We demonstrate the viability and potential of this new probe by conducting in vivo experiments on mice. Because of the proposed compact structure, both action potentials of individual neurons and local field potentials (LFP) at the thalamus region of a mouse brain were successfully detected with a noise level of ~30 μVpp. Furthermore, we successfully induced absence seizure by injecting seizure-inducing drugs (baclofen) at a local target region and observed distinctive changes in neural signal patterns. Specifically, spike–wave discharge (SWD), which is an indicative signal pattern of absence seizure, was successfully recorded. These signals were also directly compared to SWD detected after inducing absence seizure through direct injection of baclofen through the abdomen. This work demonstrates the potential of our multi-functional neural probes for use in effective investigation of brain functions and disorders by using widely available mouse models. [ABSTRACT FROM AUTHOR]

Aniridia classically presents with a bilateral congenital absence or malformation of the irides, foveal hypoplasia, and nystagmus, and patients tend to develop visually significant pre-senile cataracts and keratopathy. Additionally, they are at high risk for developing glaucoma. Classic aniridia can be genetically defined as the presence of a PAX6 gene deletion or loss-of-function mutation that results in haploinsufficiency. Variants of aniridia, which include a condition previously referred to as autosomal dominant keratitis, are likely due to PAX6 mutations that lead to partial loss of PAX6 function. Aniridia-associated keratopathy (AAK) is a progressive and potentially debilitating problem affecting aniridic patients. The current treatments for AAK are to replace the limbal stem cells through keratolimbal allograft (KLAL) with or without subsequent keratoplasty for visual rehabilitation, or to implant a Boston type 1 keratoprosthesis. Future therapies for AAK may be aimed at the genetic modification of corneal limbal stem cells. [ABSTRACT FROM AUTHOR]

Abstract: Sensing of carbon dioxide (CO2) using inexpensive, miniaturized, and highly sensitive sensors is of great interest for environmental and consumer applications. In this paper, we present four functionalization layers that are suitable for resonant sensors based on mass-loading for CO2 detection. We compare the volume sensitivities of these layers to CO2 and relative humidity (RH) by using a highly sensitive 50-MHz capacitive micromachined ultrasonic transducer (CMUT) as a resonant sensor. Among the four functionalization layers, the layer based on a guanidine polymer exhibits the highest volume sensitivity to CO2 of 1.0ppm/Hz in N2 and 3.8ppm/Hz in air (∼45%RH). Furthermore, we report on other important characteristics of the guanidine polymer for sensing applications, including polymer saturation, regeneration, and repeatability. [Copyright &y& Elsevier]

Distributed sensing of gas-phase chemicals is a promising application for mesoporous materials when combined with highly sensitive miniaturized gas sensors. We present a direct application of a mesoporous silica thin film on a highly sensitive miniaturized resonant chemical sensor with a mass sensitivity at the zeptogram scale for relative humidity and CO2 detection. Using mesoporous silica thin-film, we report one of the lowest volume resolutions and a sensitive detection of 5.1 × 10-4% RH/Hz to water vapor in N2, which is 70 times higher than a device with a nontemplated silica layer. In addition, a mesoporous thin-film that is functionalized with an amino-group is directly applied on the resonant sensor, which exhibits a volume sensitivity of 1.6 × 10-4%/Hz and a volume resolution of 1.82 × 10-4% to CO2 in N2. [ABSTRACT FROM AUTHOR]

Distributed sensing of gas-phase chemicals using highly sensitive and inexpensive sensors is of great interest for many defense and consumer applications. In this paper we present ppb-level detection of dimethyl methylphosphonate (DMMP), a common simulant for sarin gas, with a ppt-level resolution using an improved capacitive micromachined ultrasonic transducer (CMUT) as a resonant chemical sensor. The improved CMUT operates at a higher resonant frequency of 47.7 MHz and offers an improved mass sensitivity of 48.8 zg/Hz/μm2 by a factor of 2.7 compared to the previous CMUT sensors developed. A low-noise oscillator using the CMUT resonant sensor as the frequency-selective device was developed for real-time sensing, which exhibits an Allan deviation of 1.65 Hz (3s) in the presence of a gas flow; this translates into a mass resolution of 80.5 zg/μm2. The CMUT resonant sensor is functionalized with a 50-nm thick DKAP polymer developed at Sandia National Laboratory for dimethyl methylphosphonate (DMMP) detection. To demonstrate ppb-level detection of the improved chemical sensor system, the sensor performance was tested at a certified lab (MIT Lincoln Laboratory), which is equipped with an experimental chemical setup that reliably and accurately delivers a wide range of low concentrations down to 10 ppb. We report a high volume sensitivity of 34.5 ± 0.79 pptv/Hz to DMMP and a good selectivity of the polymer to DMMP with respect to dodecane and 1-octanol. [ABSTRACT FROM AUTHOR]

Mammalian gonad differentiation involves sexually dimorphic cell-fate decisions within the bipotential gonadal primordia. Testis differentiation is initiated by a center-to-poles wave of Sry expression that induces supporting cell precursors (SCPs) to become Sertoli rather than granulosa cells. The initiation of ovary differentiation is less well understood. We identified two novel SCP markers, 1700106J16Rik and Sprr2d, whose expression is ovary-biased during early gonad development, and altered in Wnt4, Sf1, Wt1, and Fog2 mutant gonads. In XX and XY gonads, both genes were up-regulated at ∼E11 in a center-to-poles wave, and then rapidly down-regulated in XY gonads in a center-to-poles wave, which is reminiscent of Sry expression in XY gonads. Our data suggest that 1700106J16Rik and Sprr2d may have important roles in early gonad development, and are consistent with the hypothesis that ovarian SCP differentiation occurs in a center-to-poles wave with similar timing to that of testicular SCP differentiation. Developmental Dynamics 238:812-825, 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The development of portable volatile organic compound (VOC) sensors is essential for home healthcare and workplace safety because VOCs are environmental pollutants that may critically affect human health. Here, we report a compact and portable sensor platform based on a capacitive micromachined ultrasonic transducer (CMUT) array offering multiplex detection of various VOCs (toluene, acetone, ethanol, and methanol) using a single read-out system. Three CMUT resonant devices were functionalized with three different layers: (1) phenyl-selective peptide, (2) colloids of single-walled nanotubes and peptide, and (3) poly(styrene-co-allyl alcohol). As each device exhibited different sensitivities to the four VOCs, we performed principal component analysis to achieve selective detection of all four gases. For the simultaneous detection of VOCs using CMUT sensors, the changes in the resonant frequencies of three devices were monitored in real time, but using only a single oscillator through an electrically controlled relay to achieve compactness. In addition, by devising a wireless system, measurement results were transmitted to a smartphone to monitor the concentration of VOCs. We used multiple sensors to obtain a larger number of fingerprints for pattern recognition to enhance selectivity but interfaced these sensors with a single read-out circuit to minimize the footprint of the overall system. The compact CMUT-based sensor array based on a multiplex detection scheme is a promising sensor platform for portable VOC monitoring. [ABSTRACT FROM AUTHOR]

Chronic monitoring of bladder activity and urine volume is essential for patients suffering from urinary dysfunctions. However, due to the anatomy and dynamics of the bladder, chronic and precise monitoring of bladder activity remains a challenge. Here, we propose a new sensing mechanism that measures the bladder volume using a resistive ladder network with contact switches. Instead of measuring the impedance between the electrode continuously, the proposed sensor provides a digitized output (‘on’ or ‘off’) when the bladder volume reaches a certain threshold value. We present simple proof-of-concept sensors which compare the discrete-mode operation to the continuous-mode operation. In addition, by using multiple pairs of this contact-mode switch in a resistor ladder structure, we demonstrate monitoring of the bladder volume in four discrete steps using an idealized balloon and an ex vivo pig’s bladder. We implemented the resistive ladder network using a conductive polypyrrole/agarose hydrogel composite which exhibits a Young’s modulus comparable to that of the bladder wall. Compared to the continuous-mode operation, the proposed sensing mechanism is less susceptible to drift due to material degradation and environmental factors. [ABSTRACT FROM AUTHOR]

To determine whether patient satisfaction with oral sedation is noninferior to intravenous sedation for cataract surgery. Prospective, randomized, double-masked clinical trial. A volunteer sample of patients 18 years or older from diverse backgrounds scheduled for cataract surgery. Patients who were allergic to benzodiazepines, older than 70 years with a failed delirium screening questionnaire, pregnant or nursing, using a medication inhibiting cytochrome 450 3A, or intoxicated on the day of surgery were excluded. Patients were randomized to receive either oral triazolam with intravenous placebo or intravenous midazolam with oral placebo before surgery. The primary outcome was patient satisfaction, measured by a survey administered on postoperative day 1. Secondary outcomes included surgeon and anesthesia provider satisfaction, need for supplemental anesthesia, and surgical complications. Among the 85 patients (42 men [49.4%]; mean age, 65.8 years; standard deviation, 9.5 years) completing the study, the mean satisfaction score was 5.34±0.63 (range, 3.75–6) in the oral sedation group and 5.40±0.52 (range, 4–6) in the intravenous group. With an a priori noninferiority margin of 0.5 and a difference in mean scores between the 2 groups of 0.06 (1-tailed 95% confidence interval [CI], –infinity to 0.27), our results demonstrate noninferiority of oral sedation with a P value of 0.0004. Surgeon and anesthesia provider satisfaction was similar between the 2 groups. Intraoperative complications occurred in 16.7% in the oral group and 9.3% in the intravenous group (difference, 7.4%; 95% CI, –6.9% to 21.6%; P = 0.31). The only major intraoperative complication—a posterior capsular tear—occurred in the intravenous group. Eight patients in the oral group (19.0%) and 3 in the intravenous group (7.0%) received supplemental intravenous sedation (difference, 12.1%; 95% CI, –2.0% to 26.2%; P = 0.097). The use of oral sedation in cataract surgery has been suggested as a cost- and space-saving measure, potentially allowing the transition of some patients from an operating to procedure room or office-based setting. We report the noninferiority of oral compared with intravenous sedation for cataract surgery in a diverse patient population in terms of patient satisfaction. [ABSTRACT FROM AUTHOR]