Planar array antenna coupled InGaAs/InAlAs multi-quantum well optical modulator for 60†GHz band millimeter wave signals.

A Fe-InP-based planar array antenna-coupled InGaAs/InAlAs multiple quantum well (MQW) optical phase modulator is proposed and demonstrated for radio over fiber (RoF) applications with 60 GHz-band millimeter-wave wireless signals. The modulator comprises five types of five-layer asymmetric coupled quantum wells (FACQWs) and a two-element array antenna. The FACQWs are designed to have a significant electric-field-induced refractive index change with small electric fields induced in the antenna. In the fabricated modulator, a carrier-to-sideband ratio (CSR) of up to 45.9 dB was successfully obtained at a power density of 11 W/m2, corresponding to a phase shift of 10.1 mrad. Furthermore, data transmission of a 2 GHz modulated wave with a 60 GHz wireless carrier wave was demonstrated.

Understanding the Role of Loss Modulus of Viscoelastic Substrates in the Evaporation Dynamics of Sessile Drops.

Viscoelastic properties of soft substrates play a crucial role in the evaporation dynamics of sessile drops. Recent studies have revealed that the modification of the viscoelastic properties of substrates changes the dynamics of the three-phase contact line, consequently affecting the evaporation behavior of sessile drops. Notably, these modifications occur without any noticeable changes to the substrate's wetting characteristics or surface topography. However, the individual role of storage (G') and loss (G″) moduli of substrates on drop evaporation dynamics remains unexplored. In this study, we investigate the evaporation dynamics of water drops on two groups of poly(dimethylsiloxane)-based viscoelastic substrates possessing either identical G' with varying G″ or identical G″ with varying G'. Our study reveals that on a substrate with constant shear modulus (G'), a reduction of an order of magnitude in loss modulus shifts the evaporation process from the constant contact radius mode to the constant contact angle mode. We hypothesize that this observed shift in behavior stems from the varying viscoelastic dissipation influenced by the plateau modulus and characteristic relaxation time of polymer gels. Our hypothesis is further supported from the observation that the evaporation process persists on the substrate with constant loss modulus (G″). Our study advances the current understanding of drop evaporation on soft substrates that may find potential applications involving soft composites, biological entities, tissue engineering, and wearable electronics.

Dilute polyelectrolyte solutions: recent progress and open questions.

Polyelectrolytes are a class of polymers possessing ionic groups on their repeating units. Since counterions can dissociate from the polymer backbone, polyelectrolyte chains are strongly influenced by electrostatic interactions. As a result, the physical properties of polyelectrolyte solutions are significantly different from those of electrically neutral polymers. The aim of this article is to highlight key results and some outstanding questions in the polyelectrolyte research from recent literature. We focus on the influence of electrostatics on conformational and hydrodynamic properties of polyelectrolyte chains. A compilation of experimental results from the literature reveals significant disparities with theoretical predictions. We also discuss a new class of polyelectrolytes called poly(ionic liquid)s that exhibit unique physical properties in comparison to ordinary polyelectrolytes. We conclude this review by listing some key research challenges in order to fully understand the conformation and dynamics of polyelectrolytes in solutions.

Torsional fracture of viscoelastic liquid bridges.

Short liquid bridges are stable under the action of surface tension. In applications like electronic packaging, food engineering, and additive manufacturing, this poses challenges to the clean and fast dispensing of viscoelastic fluids. Here, we investigate how viscoelastic liquid bridges can be destabilized by torsion. By combining high-speed imaging and numerical simulation, we show that concave surfaces of liquid bridges can localize shear, in turn localizing normal stresses and making the surface more concave. Such positive feedback creates an indent, which propagates toward the center and leads to breakup of the liquid bridge. The indent formation mechanism closely resembles edge fracture, an often undesired viscoelastic flow instability characterized by the sudden indentation of the fluid's free surface when the fluid is subjected to shear. By applying torsion, even short, capillary stable liquid bridges can be broken in the order of 1 s. This may lead to the development of dispensing protocols that reduce substrate contamination by the satellite droplets and long capillary tails formed by capillary retraction, which is the current mainstream industrial method for destabilizing viscoelastic liquid bridges.

Social Support and Associated Factors Among Men and Women in Pre-COVID Substance Use Treatment.

Low levels of social support are related to negative health outcomes, representing further obstacles to recovery from substance use disorder (SUD). This study examined relationships among stressors, symptoms and social support in 124 women and 102 men engaged in two outpatient public sector substance use treatment programs. Multiple linear regression analyses were utilized to assess relationships between variables of interest and social support. Men reported significantly lower social support than women. Food insecurity was associated with lower social support for men (ß= -13.6 [95% CI -26.7, -0.4], p = 0.04). When examining emotional support and tangible aid, victimization history was related to lower support (both types) for women while food insecurity was associated with lower support (both types) for men. Depression was related to lower emotional support among both men and women. Substance use treatment programs should explicitly target social support and related stressors to facilitate recovery for the individuals they serve.

Temperature-independent lasing wavelength of highly stacked InAs quantum dot laser fabricated on InP(311)B substrate with Bi irradiation.

In this study, the effects of bismuth (Bi) irradiation on InAs quantum dot (QD) lasers operating in the telecommunication wavelength band were investigated. Highly stacked InAs QDs were grown on an InP(311)B substrate under Bi irradiation, and a broad-area laser was fabricated. In the lasing operation, the threshold currents were almost the same, regardless of Bi irradiation at room temperature. These QD lasers were operated at temperatures between 20 and 75°C, indicating the possibility of high-temperature operation. In addition, the temperature dependence of the oscillation wavelength changed from 0.531 nm/K to 0.168 nm/K using Bi in the temperature range 20-75°C.

Entry Site Is Associated With Aortic Enlargement After Pre-emptive Endovascular Repair for Uncomplicated Type B Aortic Dissection.

OBJECTIVES: We aimed to examine the mid-term results corresponding to the entry site in patients who underwent pre-emptive thoracic endovascular aortic aneurysm repair (TEVAR) for uncomplicated type B aortic dissection (TBAD). METHODS: We included 27 patients who underwent pre-emptive TEVAR for uncomplicated TBAD between September 2014 and December 2019. We divided the patients into 2 groups depending on the proximal landing zone (zone 2 group, zone ≥3 group) and retrospectively analyzed the risk of all-cause and aorta-related mortality, aortic events (rupture, open conversion, and secondary intervention), and aortic enlargement (≥5 mm). RESULTS: The median age of the patients was 53 (47-65) years. The median duration from the onset of uncomplicated TBAD to TEVAR was 43 (30-99) days, and the median follow-up duration was 48 (36-57) months. The maximum preoperative diameter of the dissected aorta was 40 mm in the zone 2 group and 35 mm in the zone ≥3 group (p=0.134). There was no case of hospital death or spinal cord ischemia; however, there was 1 (3.7%) case of perioperative stroke in the zone 2 group. Multivariate analysis of the risk factors for aortic enlargement following pre-emptive TEVAR for uncomplicated TBAD revealed that only zone 2 landing was an independent risk factor. The estimated Kaplan-Meier curve showed a higher rate of aortic enlargement in the zone 2 group at 4 years after pre-emptive TEVAR (46.4% vs 0%, log-rank test; p=0.011). CONCLUSIONS: In this study on TBAD, we found that zone 2 landing was associated with aortic enlargement after pre-emptive TEVAR. In cases where the distance from the left subclavian artery to a major entry point was short, there were more cases of aortic dilatation. CLINICAL IMPACT: The effectiveness of entry closure for type B aortic dissection was demonstrated in the INSTEAD XL trial. The cause of aortic enlargement after pre-emptive endovascular treatment for type B aortic dissection remains controversial. In the present study, zone 2 landing was a risk factor for aortic enlargement after pre-emptive thoracic endovascular aortic aneurysm repair (TEVAR) for uncomplicated type B dissection. Patients with zone 2 landing should be closely followed up after pre-emptive TEVAR.

Mortality and morbidity of extremely low birth weight infants in Japan, 2015.

BACKGROUND: In Japan, the mortality rate of extremely low birth weight (ELBW) infants is notably low in comparison with other developed countries, but the prevalence of chronic lung disease (CLD) and retinopathy of prematurity (ROP) is relatively high. This study aimed to estimate the mortality and morbidity of ELBW infants born in 2015 who were admitted to neonatal intensive care units (NICUs) in Japan and to examine the factors that affected the short-term outcomes of these infants. We also compared the mortality of ELBW infants born in 2005, 2010, and 2015. METHODS: We analyzed the mortality, morbidity, and factors related to short-term outcomes of ELBW infants, using data from 2782 infants born in 2015 and registered at NICUs in Japan. RESULTS: The mortality rates during NICU stays were 17.0%, 12.0%, and 9.8% for ELBW infants born in 2005, 2010, and 2015, respectively. Among ELBW infants born in 2015, multiple logistic regression analysis showed that short gestational age and low birthweight Z-score contributed to the increased risk of death. Births by cesarean section and antenatal corticosteroid administration were significantly associated with a reduced risk of death. Among infants who survived, CLD was observed in 53.1% and ROP requiring treatment was observed in 30.4%. CONCLUSIONS: Mortality in ELBW infants decreased significantly from 2005 to 2015. As CLD and ROP may affect quality of life and long-term outcomes of infants who survived, prevention strategies and management for these complications are critical issues in neonatal care in Japan.

Evaluating Technologies to Identify Fentanyl and Adulterants in Street Drug Paraphernalia: Qualitative Perspectives of Service Providers and Their Clientele.

Background: Opioid overdose deaths continue to present major public health challenges in the U.S. Harm reduction agencies have begun using drug checking technologies to identify adulterants in the local drug supply and reduce overdose risk among people who use drugs (PWUD). Through qualitative and ethnographic methods, we assess the use of portable mass spectrometers at a harm reduction agency in a Northeastern U.S. city. Methods: We conducted participant observation, and on-the-spot qualitative interviews with harm-reduction staff members (n = 10) and their clientele (n = 17) between May 2019 and December 2020. Interviews explored emic views on drug checking (process, logistics, technology), and perceived benefits and challenges. We used thematic content analysis techniques to code and analyze interview transcriptions. Results: Implementation and use of drug checking devices were not free of challenges and malfunctions, often delaying drug checking opportunities and increasing suspicions and distrust among clients. Yet, staff members perceived that when working properly, or in conjunction with an additional device, they offered information about purchased drugs that could empower clients and potentially lead to positive behavior change. Use of these devices also enhanced engagement between harm reduction staff and PWUD, facilitating meaningful conversations around self-advocacy and harm reduction engagement. Conclusion: We report qualitative findings on the experiences and perceptions of drug checking devices among harm reduction staff and PWUD. Our findings indicate that use of this technology has the potential to decrease risk behaviors, expand health promotion services, and help reduce high rates of fentanyl-related overdose.

Effect of dopamine receptor-related compounds on naïve common marmosets for auditory steady-state response.

Abnormalities of auditory steady-state responses (ASSRs) and the effects of antipsychotic drugs on ASSRs have been investigated in patients with schizophrenia. It is presumed that drugs do not directly affect ASSRs because its abnormalities are associated with schizophrenia. Therefore, to investigate the direct effect of drugs on ASSRs, we established an ASSR evaluation system for common marmosets in a naïve state. Dopamine D1 receptor stimulation (SKF-81297, 2 mg/kg ip) significantly increased evoked power (EP) at 40 Hz. The phase locking factor (PLF) was increased significantly at 20, 30, 40, and 80 Hz. However, administration of a dopamine D1 receptor antagonist (SCH-39166, 0.3 mg/kg ip) resulted in a significant decrease in EP and PLF at 30 Hz. Dopamine D2 receptor stimulation (quinpirole, 1 mg/kg im) tended to increase EP and induced power (IP) at all frequencies, and a significant difference was observed at 30 Hz IP. There was no change in PLF at all frequencies. In addition, dopamine D2 receptor blockade (raclopride, 3 mg/kg ip) reduced EP and PLF at 30 Hz. Subcutaneous administration of the serotonin dopamine antagonist, risperidone (0.3 mg/kg), tended to increase IP and decrease PLF, but not significantly. Taken together, it is possible to compare the differences in the mode of action of drugs on ASSRs using naïve nonhuman primates.NEW & NOTEWORTHY We measured the effects of dopamine receptor-related compounds on ASSR in marmosets. D1 receptor stimulation increased the phase locking factor (PLF) and evoked power (EP), and reduced the induced power (IP). D2 receptor stimulation increased the IP. D1 and D2 receptor blockers reduced the PLF and EP at 30 Hz. Different modes of action of various drugs related to psychiatric disorders were evaluated by administering antipsychotic drugs to naïve marmosets.

A rapid and simple spectroscopic method for the determination of yeast cell viability using methylene blue.

Determination of cell viability is important in various microbiological studies. The microscopic method, counting dead cells stained by methylene blue (MB), has often been used for the determination of viability, although it is not efficient for the measurement of a large number of samples. Alternatively, some spectroscopic methods have been proposed to avoid tedious cell counting. One of these proposed methods detects the decrease in MB absorbance in the supernatant of cell suspension, because dead cells incorporate MB more efficiently than viable cells. However, at present, this spectroscopic method is rarely used due to its low throughput. Therefore, we devised a small-scale, rapid and simple method by improving several points as follows. (1) The peak wavelength of MB absorbance, 665 nm, was used to detect MB efficiently at the microtube scale. (2) The composition of the MB solution was improved by adding trisodium citrate. (3) The reaction time was shortened. And (4) the concentration ranges of both MB and cells, with which absorbance is linearly related to cell viability, were determined. The improved method enabled us to evaluate the dose-dependent toxicities of alcohols, antifungal/antimalarial quinacrine, and UV-C irradiation. The results were compatible with those of conventional microscopic counting and colony formation. The method would be applicable to automated determination and to various organisms such as bacteria and filamentous fungi which are difficult to be counted microscopically.

Rheological scaling of ionic-liquid-based polyelectrolytes in ionic liquid solutions: the effect of the ion diameter of ionic liquids.

We investigate the effect of the ion diameter a of ionic liquids (ILs) on the shear viscosity of polymerized ionic liquids (PILs) in IL solutions. When both the PIL and IL contain large PFSI anions (a ≈ 0.57 nm), the specific viscosity ηsp first decreases with increasing IL concentration cIL in the low cIL regime, reaches a minimum and then increases with increasing cIL in the high cIL regime. By comparing the measured ηsp with the modified charge screening model proposed in our previous study [Matsumoto et al., Macromolecules, 2021, 54, 5648-5661], we attribute the observed non-monotonic trend of ηsp against cIL to the charge underscreening phenomenon, i.e., an increase of the screening length at high cIL leads to the upturn of ηsp. On the other hand, when the PIL and IL contain small BF4 anions (a ≈ 0.34 nm), the ηsp decreases asymptotically with increasing cIL, because the charge on the PIL chain is likely screened fully in the entire cIL regime. Our results demonstrate that the ion diameter of ILs plays an important role in governing the charge screening mechanism of PILs in IL solutions, and thus influencing the viscoelastic properties of PIL solutions.

[A case of unresectable intrahepatic cholangiocarcinoma receiving sustainable pembrolizumab therapy].

A 65-year-old man had unresectable intrahepatic cholangiocarcinoma with a malignant biliary stricture. We used an endoscopic plastic stent to drain the bile. Despite receiving standard chemotherapy, the tumor eventually progressed and cancerous peritonitis developed. We had to exchange plastic stents frequently because of stent occlusion. We had a re-biopsy with EUS-FNA and tested for microsatellite instability, which came back as MSI-high. We administered pembrolizumab, which resulted in a significant reduction of tumor size. We were able to administer long-term chemotherapy without serious side effects by repeatedly exchanging plastic stents for stent occlusion. He has maintained partial response for more than 20 months after receiving pembrolizumab.

[A case of SIADH due to pancreatic cancer was improved by tolvaptan].

We report the case of a 68-year-old man, who presented in emergency care with inarticulate speech. The patient was diagnosed with syndrome of inappropriate antidiuretic hormone (SIADH) associated with pancreatic cancer. All diagnostic criteria for SIADH were met, and cancer of the pancreatic tail was identified by computed tomography. Standard treatment for SIADH includes water restriction, oral NaCl, continuous intravenous infusion of 3% NaCl, and intravenous infusion of furosemide. However, these treatments have varying effectiveness and are difficult for both patients and medical staff. Furthermore, unless treatment of the underlying disease is successful, continued hospitalization is needed and the patient's quality of life is significantly impaired. In this case, hyponatremia improved with this standard treatment, but ascites and edema developed. We treated the patient with tolvaptan due to decreased cardiac function, and symptoms improved rapidly. Although surgery and chemotherapy could not be performed for pancreatic cancer, the SIADH was treated for 7 months without relapse. In summary, a case of SIADH complicated by pancreatic cancer was difficult to control with standard treatment, but responded rapidly to tolvaptan, and outpatient treatment could be continued for a long period. Tolvaptan is useful for the treatment of SIADH associated with cancer.

[A case of thrombotic microangiopathy during chemotherapy with gemcitabine in a patient with pancreatic cancer].

A 57-year-old male patient with unresectable pancreatic head cancer was treated with chemotherapy, 5 courses of gemcitabine plus nab paclitaxel therapy, and 9 courses of gemcitabine monotherapy. After 12 months of treatment, he was admitted to our hospital with headache and dyspnea. He was diagnosed with gemcitabine-induced thrombotic microangiopathy (TMA) due to acute kidney dysfunction, hemolytic anemia, and thrombocytopenia. Gemcitabine was discontinued, and symptoms were improved without using hemodialysis and plasma exchange. After his renal function recovered, we started S-1 chemotherapy. Eighteen months later, the patient was alive. Looking back, we realized that fragment red blood cells appeared in complete blood count and serum LDH elevated at 5 months prior to admission, serum creatinine level increased slowly at 4 months prior to admission, and blood pressure elevated significantly at 2 months prior to admission. Therefore, physicians must be aware of TMA as a possible adverse event to gemcitabine. As in this case, hemolytic findings and hypertension in patients treated with gemcitabine may help early detection of TMA.

Fast dynamics of low-frequency fluctuations in a quantum-dot laser with optical feedback.

We experimentally investigate the complex dynamics of a multi-mode quantum-dot semiconductor laser with time-delayed optical feedback. We examine a two-dimensional bifurcation diagram of the quantum-dot laser as a comprehensive dynamical map by changing the injection current and feedback strength. We found that the bifurcation diagram contains two different parameter regions of low-frequency fluctuations. The power-dropout dynamics of the low-frequency fluctuations are observed in the sub-GHz region, which is considerably faster than the conventional low-frequency fluctuations in the MHz region. Comparing the dynamics of quantum-dot laser with those of single- and multi-mode quantum-well semiconductor lasers reveals that the fast low-frequency fluctuation dynamics are unique characteristics of quantum-dot lasers with time-delayed optical feedback.

Comparative study of commercial protocols for high recovery of high-purity mesenchymal stem cell-derived extracellular vesicle isolation and their efficient labeling with fluorescent dyes.

The extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) can be used as carriers for therapeutic molecules and drugs to target disordered tissues. This aimed to compare the protocols used for isolation of MSC-derived EVs by comparing EV collection conditions and three commercial purification kits. We also determined appropriate fluorescent dyes for labeling EVs. MSC-derived EVs were efficiently secreted during cell growth and highly purified by the phosphatidyl serine-based affinity kit. Although the EV membrane was more efficiently labeled with the fluorescent dye PKH67 compared to other probes, the efficiency was not enough to accurately analyze the endothelial cellular uptake of EVs. Results verified the easy protocol for isolating and fluorescently labeling EVs with commercial reagents and kits, but meanwhile, further modification of the protocol is required in order to scale up the amount of EVs derived from MSCs using fluorescent probes.

Comparing risk factors associated with the late detection of critical congenital heart disease at different facility levels.

AIMS: Critical congenital heart disease (CCHD) requires surgery or catheter intervention within the first year of life; delayed diagnoses result in worsened outcomes. In Japan, there are few reports of delayed CCHD diagnosis. We investigated the diagnoses and factors associated with the late detection of CCHD. METHODS: This retrospective cohort study evaluated 88 CCHD infants admitted to a level IV facility. We compared the late detection rates across facility levels of neonatal care and CCHD characteristics. RESULTS: Critical congenital heart disease was identified prenatally in 46 (52%) infants: early (≤3 days postnatally) in 29 (33%) and late (≥4 days postnatally) in 13 (15%). The oxygen saturation of 27 of 29 infants with early detection and 7 of 13 infants with late detection was measured using pulse oximetry within 3 days postnatally. Factors associated with the late detection of CCHD were lack of clinical recognition of symptoms in five infants, referral to higher-level facilities after discharge in four infants, and definitive diagnosis not confirmed using echocardiography in four infants. The most common factors associated with late detection were referral to higher-level facilities after discharge in level I facilities and definitive diagnosis not confirmed using echocardiography in level II facilities. CONCLUSION: Critical congenital heart disease may require advanced knowledge and echocardiographic techniques for diagnosis. Pulse oximetry and telemedicine should also be incorporated in the diagnostic algorithm. Improvement in these factors might contribute to reducing the late detection of CCHD.

Structural Studies of Overlapping Dinucleosomes in Solution.

An overlapping dinucleosome (OLDN) is a structure composed of one hexasome and one octasome and appears to be formed through nucleosome collision promoted by nucleosome remodeling factor(s). In this study, the solution structure of the OLDN was investigated through the integration of small-angle x-ray and neutron scattering (SAXS and SANS, respectively), computer modeling, and molecular dynamics simulations. Starting from the crystal structure, we generated a conformational ensemble based on normal mode analysis and searched for the conformations that reproduced the SAXS and SANS scattering curves well. We found that inclusion of histone tails, which are not observed in the crystal structure, greatly improved model quality. The obtained structural models suggest that OLDNs adopt a variety of conformations stabilized by histone tails situated at the interface between the hexasome and octasome, simultaneously binding to both the hexasomal and octasomal DNA. In addition, our models define a possible direction for the conformational changes or dynamics, which may provide important information that furthers our understanding of the role of chromatin dynamics in gene regulation.

Rheology of the Electric Double Layer in Electrolyte Solutions.

Electric double layers (EDLs) are ionic structures formed on charged surfaces and play an important role in various biological and industrial processes. An extensive study in the past decade has revealed the structure of the EDL in concentrated electrolyte solutions of both ordinary salts and ionic liquids. However, how the EDL structure affects their material properties remains a challenging topic due to technical difficulties of these measurements at nanoscale. In this work, we report the first detailed characterization of the viscoelasticity of the EDL formed over a wide range of ion concentrations, including concentrated electrolyte solutions. Specifically, we investigate the complex shear modulus of the EDL by measuring the resonant frequency and the energy dissipation of a quartz crystal microbalance (QCM), a surface-sensitive device, immersed in aqueous solutions containing three types of solutes: an ionic liquid, 1-butyl-3-methylimidazolium chloride (BmimCl); an ordinary salt, sodium chloride (NaCl); and a nonelectrolyte, ethylene glycol (EG). For the two electrolyte solutions, we observe a monotonic decrease in the resonant frequency and a monotonic increase in the energy dissipation with increasing ion concentrations due to the presence of the EDL. The complex shear modulus of the EDL is estimated through a wave propagation model in which the density and shear modulus of the EDL decay exponentially toward those of the bulk solution. Our results show that both the storage and the loss modulus of the EDL increase rapidly with increasing ion concentrations in the low ion concentration regime (<1 M) but reach saturation values with similar magnitude at a sufficiently high ion concentration. The shear viscosity of the EDL near the charged QCM surface is approximately 50 times for NaCl solutions and 500 times for BmimCl solutions of the bulk solution value at the saturation concentration. We also demonstrate that QCM can be utilized for analyzing the rheological properties of the EDL, thus providing a complementary, low-cost, and portable alternative to conventional laboratory instruments such as the surface force apparatus. Our results elucidate new perspectives on the viscoelastic properties of the EDL and can potentially guide device optimization for applications such as biosensing and fast charging of batteries.