The Diels-Alder Cross-Linked Gelatin/Dextran Nanocomposite Hydrogels with Silver Nanoparticles for Wound Healing Applications: Synthesis, Characterization, and In Vitro Evaluation.

Wound healing involves a sophisticated biological process that relies on ideal conditions to advance through various stages of repair. Modern wound dressings are designed to imitate the natural surroundings around cells and offer properties such as moisture regulation, strength, and antimicrobial defense to boost healing. A recent research project unveiled a new type of gelatin (Gel)/dextran (Dex) hydrogels, linked through Diels-Alder (D-A) reactions, loaded with silver nanoparticles (Ag-NPs) for cutting-edge wound treatment. Gel and Dex were chemically modified to form the hydrogels via the D-A reaction. The hydrogels were enriched with Ag-NPs at varying levels. Thorough analyses of the hydrogels using methods like NMR, FT-IR, and SEM were carried out to assess their structure and nanoparticle integration. Rheological tests displayed that the hydrogels had favorable mechanical attributes, particularly when Ag-NPs were included. The hydrogels demonstrated controlled swelling, responsiveness to pH changes, and were non-toxic. Testing against E. coli showcased the strong antibacterial activity of the nanocomposite hydrogels in a concentration-dependent manner. This investigation showcased the promise of these bioactive nanocomposite hydrogels in promoting speedy wound healing by maintaining a moist environment, offering an antimicrobial shield, and ensuring mechanical support at the wound site.

Recent advances in soft, implantable electronics for dynamic organs.

Unlike conventional rigid counterparts, soft and stretchable electronics forms crack- or defect-free conformal interfaces with biological tissues, enabling precise and reliable interventions in diagnosis and treatment of human diseases. Intrinsically soft and elastic materials, and device designs of innovative configurations and structures leads to the emergence of such features, particularly, the mechanical compliance provides seamless integration into continuous movements and deformations of dynamic organs such as the bladder and heart, without disrupting natural physiological functions. This review introduces the development of soft, implantable electronics tailored for dynamic organs, covering various materials, mechanical design strategies, and representative applications for the bladder and heart, and concludes with insights into future directions toward clinically relevant tools.

Synthesis of shape-programmable elastomer for a bioresorbable, wireless nerve stimulator.

Materials that have the ability to manipulate shapes in response to stimuli such as heat, light, humidity and magnetism offer a means for versatile, sophisticated functions in soft robotics or biomedical implants, while such a reactive transformation has certain drawbacks including high operating temperatures, inherent rigidity and biological hazard. Herein, we introduce biodegradable, self-adhesive, shape-transformable poly (L-lactide-co-ε-caprolactone) (BSS-PLCL) that can be triggered via thermal stimulation near physiological temperature (∼38 °C). Chemical inspections confirm the fundamental properties of the synthetic materials in diverse aspects, and study on mechanical and biochemical characteristics validates exceptional stretchability up to 800 % and tunable dissolution behaviors under biological conditions. The integration of the functional polymer with a bioresorbable electronic system highlights potential for a wide range of biomedical applications.

Analysis of the Dielectric Properties of Alkali-Free Aluminoborosilicate Glasses by Considering the Contributions of Electronic and Ionic Polarizabilities in the GHz Frequency Range.

Recently, the investigation of the dielectric properties of glasses in the GHz frequency range has attracted great interest for use in printed circuit boards (PCBs) as a reinforcing material in the application of high-speed 5G/6G communications. In particular, glasses with low dielectric properties are a prerequisite for high-frequency applications. In this study, the GHz dielectric properties of alkali-free aluminoborosilicate glasses without and with La2O3 were analyzed using the Clausius-Mossotti equation where both the electronic and ionic polarizabilities contribute to the dielectric constant. The dielectric polarizability (αD) and oxide ion polarizability (αO2-) were calculated from the measured dielectric constant (εGHz) at 1 GHz and the glass density. The dielectric constants (εopt) at the optical frequencies and electronic polarizabilities (αe) of the glasses were calculated from the refractive index measured at 633 nm and the glass density. The εGHz values were found to be significantly higher than the εopt values in both series of glasses, due to the ionic polarizability (αi), which contributes additionally to the εGHz. The lower dielectric constants of the La2O3-incoporated glasses than that of the reference glass without La2O3 may be due to the lower ionic polarizability originated from the incorporation of the high cation field strength of the La3+ ions.

Customizable Nichrome Wire Heaters for Molecular Diagnostic Applications.

Accurate sample heating is vital for nucleic acid extraction and amplification, requiring a sophisticated thermal cycling process in nucleic acid detection. Traditional molecular detection systems with heating capability are bulky, expensive, and primarily designed for lab settings. Consequently, their use is limited where lab systems are unavailable. This study introduces a technique for performing the heating process required in molecular diagnostics applicable for point-of-care testing (POCT), by presenting a method for crafting customized heaters using freely patterned nichrome (NiCr) wire. This technique, fabricating heaters by arranging protrusions on a carbon black-polydimethylsiloxane (PDMS) cast and patterning NiCr wire, utilizes cost-effective materials and is not constrained by shape, thereby enabling customized fabrication in both two-dimensional (2D) and three-dimensional (3D). To illustrate its versatility and practicality, a 2D heater with three temperature zones was developed for a portable device capable of automatic thermocycling for polymerase chain reaction (PCR) to detect Escherichia coli (E. coli) O157:H7 pathogen DNA. Furthermore, the detection of the same pathogen was demonstrated using a customized 3D heater surrounding a microtube for loop-mediated isothermal amplification (LAMP). Successful DNA amplification using the proposed heater suggests that the heating technique introduced in this study can be effectively applied to POCT.

Effects of Early Initiation of Polymyxin B Hemoperfusion Therapy in Patients with Cancer with Refractory Septic Shock.

Background: We aimed to analyze the correlation between in-hospital mortality and hemodynamic changes, using polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) initiation time in patients with cancer with refractory septic shock. Methods: Forty-six patients with cancer who received PMX-DHP for refractory septic shock were retrospectively analyzed and classified into early (≤3 h between refractory septic shock and PMX-DHP; n = 17) and late (>3 h; n = 29) initiation groups. The vasopressor inotropic score (VIS), sequential organ failure assessment (SOFA) score, and lactate clearance before and 24 h post-PMX-DHP were compared. Results: Overall, 52.17% died from multiple organ dysfunction, with a lower mortality rate in the early initiation group. The VIS and SOFA score decreased in both groups, but the magnitude of decrease was not significant. Lactate clearance improved in both groups, with greater improvement in the early initiation group. Univariable analysis identified associations of in-hospital mortality with early initiation, ΔC-reactive protein, lactate clearance, ΔSOFA score, and ΔVIS. Multivariable analysis demonstrated associations of in-hospital mortality risk with ΔSOFA score and early PMX-DHP initiation. Overall survival was higher in the early initiation group. Early initiation of PMX-DHP in patients with cancer with refractory septic shock reduced in-hospital mortality and improved lactate clearance.

Highly Elastic, Bioresorbable Polymeric Materials for Stretchable, Transient Electronic Systems.

Substrates or encapsulants in soft and stretchable formats are key components for transient, bioresorbable electronic systems; however, elastomeric polymers with desired mechanical and biochemical properties are very limited compared to non-transient counterparts. Here, we introduce a bioresorbable elastomer, poly(glycolide-co-ε-caprolactone) (PGCL), that contains excellent material properties including high elongation-at-break (< 1300%), resilience and toughness, and tunable dissolution behaviors. Exploitation of PGCLs as polymer matrices, in combination with conducing polymers, yields stretchable, conductive composites for degradable interconnects, sensors, and actuators, which can reliably function under external strains. Integration of device components with wireless modules demonstrates elastic, transient electronic suture system with on-demand drug delivery for rapid recovery of post-surgical wounds in soft, time-dynamic tissues.

Soft, Long-Lived, Bioresorbable Electronic Surgical Mesh with Wireless Pressure Monitor and On-Demand Drug Delivery.

Current research in the area of surgical mesh implants is somewhat limited to traditional designs and synthesis of various mesh materials, whereas meshes with multiple functions may be an effective approach to address long-standing challenges including postoperative complications. Herein, a bioresorbable electronic surgical mesh is presented that offers high mechanical strength over extended timeframes, wireless post-operative pressure monitoring, and on-demand drug delivery for the restoration of tissue structure and function. The study of materials and mesh layouts provides a wide range of tunability of mechanical and biochemical properties. Dissolvable dielectric composite with porous structure in a pyramidal shape enhances sensitivity of a wireless capacitive pressure sensor, and resistive microheaters integrated with inductive coils provide thermo-responsive drug delivery system for an antibacterial agent. In vivo evaluations demonstrate reliable, long-lived operation, and effective treatment for abdominal hernia defects, by clear evidence of suppressed complications such as adhesion formation and infections.

Delirium in patients with COVID-19 treated in the intensive care unit.

Coronavirus disease 2019 (COVID-19) can lead to acute organ dysfunction, and delirium is associated with long-term cognitive impairment and a prolonged hospital stay. This retrospective single-center study aimed to investigate the risk factors for delirium in patients with COVID-19 infection receiving treatment in an intensive care unit (ICU). A total of 111 patients aged >18 years with COVID-19 pneumonia who required oxygen therapy from February 2021 to April 2022 were included. Data on patient demographics, past medical history, disease severity, delirium, and treatment strategies during hospitalization were obtained from electronic health records. Patient characteristics and risk factors for delirium were analyzed. Old age (P < 0.001), hypertension (P < 0.001), disease severity (Sequential Organ Failure Assessment score) (P < 0.001), mechanical ventilator support (P < 0.001), neuromuscular blocker use (P < 0.001), and length of stay in the ICU (P < 0.001) showed statistically significant differences on the univariable analysis. Multivariable analysis with backward selection revealed that old age (odds ratio, 1.149; 95% confidence interval, 1.037-1.273; P = 0.008), hypertension (odds ratio, 8.651; 95% confidence interval, 1.322-56.163; P = 0.024), mechanical ventilator support (odds ratio, 226.215; 95% confidence interval, 15.780-3243.330; P < 0.001), and length of stay in the ICU (odds ratio, 30.295; 95% confidence interval, 2.539-361.406; P = 0.007) were significant risk factors for delirium. In conclusion, old age, ICU stay, hypertension, mechanical ventilator support, and neuromuscular blocker use were predictive factors for delirium in COVID-19 patients in the ICU. The study findings suggest the need for predicting the occurrence of delirium in advance and preventing and treating delirium.

Carborane-based heteromolecular extended networks driven by directional C-Te⋯N chalcogen bonding interactions.

We demonstrate that o-closo-(TeMe)2carborane directs, in the presence of linear ditopic neutral Lewis bases, the formation of co-crystals with 1D extended supramolecular networks. Specifically, the network formation is systematically stabilized by short and quasi-linear C-Te⋯N chalcogen-bonding (ChB) interactions. In sum, we report efficient carborane-based tectons to rationally design high-dimensional neutral heteromolecular networks.

Comparison of Pediatric Acute Appendicitis Before and During the COVID-19 Pandemic in New York City.

Background: Acute appendicitis (AA) is the most common abdominal surgical emergency in children and adolescents. In the year immediately following the declaration of the coronavirus disease 2019 (COVID-19) pandemic by the World Health Organization (WHO), there was a precipitous decline in emergency department (ED) visits especially for surgical conditions and infectious diseases. Fear of exposure to severe acute respiratory coronavirus 2 infection resulted in delay in presentation and time to surgery, and a shift toward more conservative management. Objective: Our goal was to compare the incidence and severity of AA before and during the COVID-19 pandemic. Methods: Patients aged 2-18 years admitted with the diagnosis of AA to Flushing Hospital Medical Center or Jamaica Hospital Medical Center in Queens, New York, were selected for chart review. Data extracted from electronic health records included demographics, clinical findings, imaging studies, and operative and pathological findings. We calculated the Alvarado score (AS) for incidence and the American Association for the Surgery of Trauma (AAST) grade for severity. We compared patients admitted between March 1, 2018-February 29, 2020 (pre-pandemic) to patients admitted between March 1, 2020-February 28, 2021 (pandemic). We then compared pre-pandemic and pandemic groups to determine differences in pediatric AA incidence and severity. Results: Of 239 patients diagnosed with AA, 184 (77%) were in the pre-pandemic group and 55 (23%) in the pandemic group. Incidence (number per year) of AA declined by 40%. The pandemic group had significantly greater overall AS of ≥7, indicating increased likelihood to require surgery, (P = 0.04) and higher AAST grade demonstrating increased severity (P = 0.02). Conclusion: There was a decline in the number of AA cases seen in our pediatric EDs and admitted during the first year of the pandemic. Clinicians need to be aware of increased severity of AA at time of presentation during public health emergencies such as a pandemic, possibly due to modified patient behavior.

Micropatterned Elastomeric Composites for Encapsulation of Transient Electronics.

Although biodegradable, transient electronic devices must dissolve or decompose via environmental factors, an effective waterproofing or encapsulation system is essential for reliable, durable operation for a desired period of time. Existing protection approaches use multiple or alternate layers of electrically inactive organic/inorganic elements combined with polymers; however, their high mechanical stiffness is not suitable for soft, time-dynamic biological tissues/skins/organs. Here, we introduce a stretchable, bioresorbable encapsulant using nanoparticle-incorporated elastomeric composites with modifications of surface morphology. Nature-inspired micropatterns reduce the diffusion area for water molecules, and embedded nanoparticles impede water permeation, which synergistically enhances the water-barrier performance. Empirical and theoretical evaluations validate the encapsulation mechanisms under strains. Demonstration of a soft, degradable shield with an optical component under a biological solution highlights the potential applicability of the proposed encapsulation strategy.

Dynamics of surface-plasmon lasing in planar metal gratings on semiconductor.

We investigate the dynamics of surface plasmon (SP) lasing in Au gratings fabricated on InGaAs with a period of around 400 nm, which locates the SP resonance near the semiconductor energy gap and facilitates efficient energy transfer. By optically pumping the InGaAs to reach the population inversion required for the amplification and the lasing, we observe SP lasing at specific wavelengths that satisfy the SPR condition depending on the grating period. The carrier dynamics in semiconductor and the photon density in the SP cavity was investigated from the time-resolved pump-probe measurement and the time resolved photoluminescence spectroscopy, respectively. Our results reveal that the photon dynamics is strongly correlated with the carrier dynamics and the lasing build-up is accelerated as the initial gain proportional to the pumping power increases, and this trend is satisfactorily explained using the rate equation model.

Ultra-stretchable and biodegradable elastomers for soft, transient electronics.

As rubber-like elastomers have led to scientific breakthroughs in soft, stretchable characteristics-based wearable, implantable electronic devices or relevant research fields, developments of degradable elastomers with comparable mechanical properties could bring similar technological innovations in transient, bioresorbable electronics or expansion into unexplored areas. Here, we introduce ultra-stretchable, biodegradable elastomers capable of stretching up to ~1600% with outstanding properties in toughness, tear-tolerance, and storage stability, all of which are validated by comprehensive mechanical and biochemical studies. The facile formation of thin films enables the integration of almost any type of electronic device with tunable, suitable adhesive strengths. Conductive elastomers tolerant/sensitive to mechanical deformations highlight possibilities for versatile monitoring/sensing components, particularly the strain-tolerant composites retain high levels of conductivities even under tensile strains of ~550%. Demonstrations of soft electronic grippers and transient, suture-free cardiac jackets could be the cornerstone for sophisticated, multifunctional biodegradable electronics in the fields of soft robots and biomedical implants.

Anastomotic leakage after resection of the rectosigmoid colon in primary ovarian cancer.

BACKGROUND: The aim of the study is to evaluate the risk factors of anastomotic leakage (AL) and develop a nomogram to predict the risk of AL in surgical management of primary ovarian cancer. METHODS: We retrospectively reviewed 770 patients with primary ovarian cancer who underwent surgical resection of the rectosigmoid colon as part of cytoreductive surgery between January 2000 to December 2020. AL was defined based on radiologic studies or sigmoidoscopy with relevant clinical findings. Logistic regression analyses were performed to identify the risk factor of AL, and a nomogram was developed based on the multivariable analysis. The bootstrapped-concordance index was used for internal validation of the nomogram, and calibration plots were constructed. RESULTS: The incidence of AL after resection of the rectosigmoid colon was 4.2% (32/770). Diabetes (OR 3.79; 95% CI, 1.31-12.69; p = 0.031), co-operation with distal pancreatectomy (OR, 4.8150; 95% CI, 1.35-17.10; p = 0.015), macroscopic residual tumor (OR, 7.43; 95% CI, 3.24-17.07; p = 0<001) and anastomotic level from the anal verge shorter than 10 cm (OR, 6.28; 95% CI, 2.29-21.43; p = 0.001) were significant prognostic factors for AL on multivariable analysis. Using four variables, the nomogram has been developed to predict anastomotic leakage: https://ALnomogram.github.io/ . CONCLUSION: Four risk factors for AL after resection of the rectosigmoid colon are identified from the largest ovarian cancer study cohort. The nomogram from this information provides a numerical risk probability of AL, which could be used in preoperative counseling with patients and intraoperative decision for accompanying surgical procedures and prophylactic use of ileostomy or colostomy to minimize the risk of postoperative leakage. TRIAL REGISTRATION: Retrospectively registered.

Wireless, Fully Implantable and Expandable Electronic System for Bidirectional Electrical Neuromodulation of the Urinary Bladder.

Current standard clinical options for patients with detrusor underactivity (DUA) or underactive bladder─the inability to release urine naturally─include the use of medications, voiding techniques, and intermittent catheterization, for which the patient inserts a tube directly into the urethra to eliminate urine. Although those are life-saving techniques, there are still unfavorable side effects, including urinary tract infection (UTI), urethritis, irritation, and discomfort. Here, we report a wireless, fully implantable, and expandable electronic complex that enables elaborate management of abnormal bladder function via seamless integrations with the urinary bladder. Such electronics can not only record multiple physiological parameters simultaneously but also provide direct electrical stimulation based on a feedback control system. Uniform distribution of multiple stimulation electrodes via mesh-type geometry realizes low-impedance characteristics, which improves voiding/urination efficiency at the desired times. In vivo evaluations using live, free-moving animal models demonstrate system-level functionality.

Predicting factors associated with prolonged intensive care unit stay of patients with COVID-19.

BACKGROUND: Predicting the length of stay (LOS) for coronavirus disease 2019 (COVID-19) patients in the intensive care unit (ICU) is essential for efficient use of ICU resources. We analyzed the clinical characteristics of patients with severe COVID-19 based on their clinical care and determined the predictive factors associated with prolonged LOS. METHODS: We included 96 COVID-19 patients who received oxygen therapy at a high-flow nasal cannula level or above after ICU admission during March 2021 to February 2022. The demographic characteristics at the time of ICU admission and results of severity analysis (Sequential Organ Failure Assessment [SOFA], Acute Physiology and Chronic Health Evaluation [APACHE] II), blood tests, and ICU treatments were analyzed using a logistic regression model. Additionally, blood tests (C-reactive protein, D-dimer, and the PaO2 to FiO2 ratio [P/F ratio]) were performed on days 3 and 5 of ICU admission to identify factors associated with prolonged LOS. RESULTS: Univariable analyses showed statistically significant results for SOFA score at the time of ICU admission, C-reactive protein level, high-dose steroids, mechanical ventilation (MV) care, continuous renal replacement therapy, extracorporeal membrane oxygenation, and prone position. Multivariable analysis showed that MV care and P/F ratio on hospital day 5 were independent factors for prolonged ICU LOS. For D-dimer, no significant variation was observed at admission; however, after days 3 and 5 days of admission, significant between-group variation was detected. CONCLUSIONS: MV care and P/F ratio on hospital day 5 are independent factors that can predict prolonged LOS for COVID-19 patients.

Expression of Peptidyl Arginine Deiminase 2 Is Closely Associated with Recurrence in Patients with Hepatocellular Carcinoma.

Peptidyl arginine deiminases (PAD) enzymes have been investigated in various cancers. Recently, PAD enzyme, in particular PAD2, has been further implicated in cancers. Although the expression of PAD2 was significantly higher in hepatocellular carcinoma (HCC) tissue, its diagnostic or prognostic role of PAD2 in HCC patients is unknown. This study investigated whether the expression of PAD2 affects recurrence and survival in HCC patients who underwent hepatic resection. One hundred and twenty-two HCC patients after hepatic resection were enrolled. The median follow-up was 41 months (range 1-213 months) in enrolled patients. To investigate an association between PAD2 expression level and the clinical characteristics of enrolled patients, the recurrence of HCC following surgical resection and survival of the patients were examined. Ninety-eight cases (80.3%) of HCC demonstrated a higher expression of PAD2. The expression of PAD2 was correlated with age, hepatitis B virus positivity, hypertension, and higher alpha-fetoprotein level. There was no association between PAD2 expression and sex, diabetes mellitus, Child-Pugh class, major portal vein invasion, HCC size or number. The recurrence rates in patients with lower PAD2 expression were higher than those with higher PAD2 expression. The cumulative survival rates of patients with higher PAD2 expression were better than those of patients with lower PAD2 expression, but it was not statistically significant. In conclusion, PAD2 expression is closely associated with recurrence of HCC patients following surgical resection.

Zebra-inspired stretchable, biodegradable radiation modulator for all-day sustainable energy harvesters.

Recent advances in passive radiative cooling systems describe a variety of strategies to enhance cooling efficiency, while the integration of such technology with a bioinspired design using biodegradable materials can offer a research opportunity to generate energy in a sustainable manner, favorable for the temperature/climate system of the planet. Here, we introduce stretchable and ecoresorbable radiative cooling/heating systems engineered with zebra stripe-like patterns that enable the generation of a large in-plane temperature gradient for thermoelectric generation. A comprehensive study of materials with theoretical evaluations validates the ability to accomplish the target performances even under external mechanical strains, while all systems eventually disappear under physiological conditions. Use of the zebra print for selective radiative heating demonstrates an unexpected level of temperature difference compared to use of radiative cooling emitters alone, which enables producing energy through resorbable silicon-based thermoelectric devices. The overall result suggests the potential of scalable, ecofriendly renewable energy systems.