Plant cell-like tip-growing polymer precipitate with structurally embedded multistimuli sensing ability.

Soft systems that respond to external stimuli, such as heat, magnetic field, and light, find applications in a range of fields including soft robotics, energy harvesting, and biomedicine. However, most of the existing systems exhibit nondirectional, nastic movement as they can neither grow nor sense the direction of stimuli. In this regard, artificial systems are outperformed by organisms capable of directional growth in response to the sense of stimuli or tropic growth. Inspired by tropic growth schemes of plant cells and fungal hyphae, here we report an artificial multistimuli-responsive tropic tip-growing system based on nonsolvent-induced phase separation of polymer solution, where polymer precipitates as its solvent dissolves into surrounding nonsolvent. We provide a theoretical framework to predict the size and velocity of growing precipitates and demonstrate its capability of sensing the directions of gravity, mechanical contact, and light and adjusting its growing direction in response. Exploiting the embedded physical intelligence of sensing and responding to external stimuli, our soft material system achieves multiple tasks including printing 3D structures in a confined space, bypassing mechanical obstacles, and shielded transport of liquids within water.

Two different jumping mechanisms of water striders are determined by body size.

Current theory for surface tension-dominant jumps on water, created for small- and medium-sized water strider species and used in bioinspired engineering, predicts that jumping individuals are able to match their downward leg movement speed to their size and morphology such that they maximize the takeoff speed and minimize the takeoff delay without breaking the water surface. Here, we use empirical observations and theoretical modeling to show that large species (heavier than ~80 mg) could theoretically perform the surface-dominated jumps according to the existing model, but they do not conform to its predictions, and switch to using surface-breaking jumps in order to achieve jumping performance sufficient for evading attacks from underwater predators. This illustrates how natural selection for avoiding predators may break the theoretical scaling relationship between prey size and its jumping performance within one physical mechanism, leading to an evolutionary shift to another mechanism that provides protection from attacking predators. Hence, the results are consistent with a general idea: Natural selection for the maintenance of adaptive function of a specific behavior performed within environmental physical constraints leads to size-specific shift to behaviors that use a new physical mechanism that secure the adaptive function.

Dynamics of self-propelled particles in vibrated dense granular media.

We study a system consisting of a few self-propelled particles (SPPs) placed among a crowd of densely packed granular particles that are vertically vibrated in a two-dimensional circular confinement. Our experiments reveal two important findings. First, an SPP exhibits a fractal renewal process within the dense granular medium, which induces a superdiffusive behavior whose diffusion exponent increases with its aspect ratio. Second, the SPPs eventually reach the boundary and form a moving cluster, which transitions from the moving state to the static state as the number of SPPs is increased. These results suggest a simple and effective method of modulating the fluidity and directionality of granular systems via controlling the shape and the number of SPPs.

Avian mud nest architecture by self-secreted saliva.

Mud nests built by swallows (Hirundinidae) and phoebes (Sayornis) are stable granular piles attached to cliffs, walls, or ceilings. Although these birds have been observed to mix saliva with incohesive mud granules, how such biopolymer solutions provide the nest with sufficient strength to support the weight of the residents as well as its own remains elusive. Here, we elucidate the mechanism of strong granular cohesion by the viscoelastic paste of bird saliva through a combination of theoretical analysis and experimental measurements in both natural and artificial nests. Our mathematical model considering the mechanics of mud nest construction allows us to explain the biological observation that all mud-nesting bird species should be lightweight.

Hierarchical Capillarity-Assisted Liquid Invasion in Multilayered Paper Channels for Nanoelectrokinetic Preconcentration.

A nanoelectrokinetic phenomenon called ion concentration polarization (ICP) has been recently applied to microfluidic paper-based devices for the high fold preconcentration of low-abundant analytes. The inherent microstructural characteristics of cellulose papers can sufficiently stabilize the chaotic electroconvection of ICP, which is a significant annoyance for typical engineered microfluidic channels. However, a high electrical voltage to induce ICP in a paper-fluidic channel can increase unavoidable electrophoretic forces over drag forces so that the preconcentrated plug is rapidly receded with severe dispersion. In order to enhance the hydraulic drag force that helps the preconcentration of analytes, here we introduce a multilayered paper structure into paper-fluidic channel. We theoretically and experimentally demonstrate that a hierarchical capillary structure in a multilayered paper-fluidic channel can effectively increase the hydraulic drag force. For the practical utility in the field of diagnostics, the mechanism is verified by a simple example of the immunoassay using biotin-streptavidin complexation.

Snap-through inversion of elastic shells swelling via solvent diffusion.

Snap-through buckling instability of elastic shells can provide a variety of biological and artificial mechanical systems with an efficient strategy to generate rapid and powerful actuation. However, snapping spherical shells studied to date have typically been shallow and thus are dominantly prone to axisymmetric inversions. Here, we study diffusion-swelling stimulated snap-through inversion of bilayer shells of a wide range of depth to cover non-axisymmetric as well as axisymmetric modes. We first establish an analytical model of strain energy stored in axisymmetrically swelling shells, in order to predict the snap-through conditions based on energy minimization. Confirming that the strain energy can indicate the critical conditions for snap-through, we compare the conditions of axisymmetric and non-axisymmetric snap-through inversion using both experiments and numerical simulations. We find that differentially swelling bilayer shells snap-through with a time-lagged but increased energy release during inversion when buckled non-axisymmetrically rather than axisymmetrically.

Swelling kinetics of constrained hydrogel spheres.

A cross-linked polymer network immersed in a solvent will absorb molecules from its surroundings, leading to transient swelling. Under the constraint of a semi-permeable membrane, the system will swell less and generate a larger internal pressure in return, a system rarely analyzed to date. We use a nonlinear poroelastic theory to model the kinetics of swelling under mechanical constraint. We find the simulation results agree well with our experimental data using hydrogel beads made of a mixture of 3-sulfopropyl acrylate potassium salt and acrylamide, bathed in water. Understanding and predicting the response speed and the actuation stress developed during the swelling of constrained hydrogels can guide the design of polymer-based soft actuators with unusually high strength.

Efficacy of a novel remotely-generated ultrasonic root canal irrigation system for removing biofilm-mimicking hydrogel from a simulated isthmus model.

AIM: To evaluate the efficacy of a novel ultrasonic irrigation device, remotely-generated irrigation with a non-invasive sound field enhancement (RINSE) system, in removing biofilm-mimicking hydrogel from a simulated isthmus model and compare it with sonically- and ultrasonically-activated irrigation systems. METHODOLOGY: A polycarbonate root canal model containing two standardized root canals (apical diameter of 0.20 mm, 4% taper, 18 mm long with a coronal reservoir) connected by three isthmuses (0.40 mm deep, 2 mm high, 4 mm long) was used as the test model. The isthmuses were filled with a hydroxyapatite powder-containing hydrogel. The canals were filled with irrigant, and the models were randomly assigned to the following activation groups (n = 15): EndoActivator (EA), ultrasonically activated irrigation (UAI), and RINSE system (RS). Syringe irrigation (SI) with a 30G needle served as the control. Standardized images of the isthmuses were taken before and after irrigation, and the amount of hydrogel removed was determined using image analysis software and compared across groups using anova (p < .05). RESULTS: Hydrogel removal was significantly higher with the RS (83.7%) than with UAI, EA, or SI (p ≤ .01). UAI (69.2%) removed significantly more hydrogel than SI and EA (p < .05), while there was no significant difference between SI (24.3%) and EA (25.7%) (p = .978). CONCLUSIONS: RINSE system resulted in the most hydrogel removal, performing better than UAI or EA. The effect of RS was also not reliant on the insert or tip entering the pulp chamber or root canal, making it particularly useful in conservative endodontics.

Development of rapid and effective oil-spill response system integrated with oil collection, recovery and storage devices for small oil spills at initial stage: From lab-scale study to field-scale test.

In the present study, through the laboratory-to-field scale experiments and trials, we report the development and evaluation of an integrated oil-spill response system capable of oil collection, recovery (separation), and storage, for a timely and effective response to the initial stage of oil-spill accidents. With the laboratory-scale experiments, first, we evaluate that the water-surface waves tend to abate the oil recovery rate below 80% (it is above 95% for the optimized configuration without the waves), which is overcome by installing the hydrophilic (and oleophobic) porous structures at the inlet and/or near the water outlet of the separator. In the follow-up meso-scale towing tank tests with a scaled-up prototype, (i) we optimize the maneuverability of the assembled system depending on the speed and existence of waves, and (ii) evaluate the oil recovery performance (more than 80% recovery for the olive oil and Bunker A fuel oil). Although more thorough investigations and improvements are needed, a recovery rate of over 50% can be achieved for the newly enforced marine fuel oil (low sulfur fuel oil, LSFO) that was not targeted at the time of development. Finally, we perform a series of field tests with a full-scale system, to evaluate the rapid deployment and operational stability in the real marine environment. The overall floating balance and coordination of each functional part are sustained to be stable during the straight and rotary maneuvers up to the speed of 5 knots. Also, the collection of the floating debris (mimicking the spilled oil) is demonstrated in the field test. The present system is now being tested by the Korea Coast Guard and we believe that it will be very powerful to prevent the environmental damage due to the oil spills.

The effects of pre-transplantation center-based cardiac rehabilitation on the postoperative quality of life and adherence to exercise in patients undergoing heart transplantation.

BACKGROUND: Heart transplantation (HTx) is the final treatment option for patients with chronic heart failure. Several studies have reported that exercise therapy, which is a component of cardiac rehabilitation, improves exercise capacity and the quality of life (QOL) in patients with heart failure. METHODS: Three patients, referred to an inpatient cardiac rehabilitation before HTx, participated in center-based cardiac rehabilitation (CBCR) during the hospitalization period. The CBCR, including aerobic exercises and resistance training, was conducted 3-4 days/week under cardiac rehabilitation team. Clinical outcomes included QOL using short form (SF)-36 questionnaire and the level of physical activity using international physical activity questionnaire (IPAQ) were evaluated before and after following the CBCR. RESULTS: These patients showed an improved QOL in physical components with mean 32% and in mental components with mean 43%. The adherence to exercise confirmed by level of physical activity also increased as much as mean 1275 MET-minutes at 3 months after transplantation. CONCLUSIONS: The findings in case report show the safety and effectiveness of CBCR in patients waiting for HTx during hopitalization. This is the first case report showing the effect of CBCR in admission period in Korean patients undergoing HTx.

Changes in working status after cancer diagnosis and socio-demographic, clinical, work-related, and psychological factors associated with it.

BACKGROUND: While many studies investigated changes in working status in cancer survivors, most studies have been performed in survivors of breast cancer and few studies evaluated factors associated with changes in the working status of cancer survivors comprehensively. We aimed to evaluate the changes in the working status of cancer survivors after diagnosis and socio-demographic, clinical, work-related and psychological factors associated with it. METHODS: We conducted a cross-sectional survey of adult patients with cancer who were working at the time of diagnosis. A trained interviewer inquired about participants' current working status, including leave of absence, discontinuing, continuing, and changing work. Sociodemographic, clinical, work-related and psychological factors were measured. Multinomial logistic regression was used to identify factors associated with changes in the working status. RESULTS: Among the 730 patients, 29%, 18% and 6% were currently on a discontinued working, leave of absence and had changed jobs, respectively. Patients who discontinued working after cancer diagnosis were more likely to be female, have ≥ $3,000 of monthly family income, not be the principal wage earners for their families and be blue-collar workers. In clinical characteristics, advanced-stage cancer and experienced cancer recurrence was associated with leave of absence and discontinued working. In work-related and psychological factors, stress due to insufficient job control (relative risk ratio [RRR] = 2.26), interpersonal conflict (RRR = 1.86), job insecurity (RRR = 2.63), organizational system (RRR = 3.49), and lack of reward (RRR = 11.76), and less meaning to work were more likely to discontinue working after a cancer diagnosis. CONCLUSION: Occupational health care professionals and other stakeholders need to openly communicate with patients with cancer about potential barriers during the return-to-work trajectory.

Real-world effectiveness of a fractional CO2 laser with topical antifungal agents for the treatment of onychomycosis.

Current therapeutic agents for onychomycosis have limited efficacy or cause side effects. Recently, successful treatment using fractional CO2 lasers has been reported; however, the results are inconsistent. We analyzed the real-world effectiveness of a Fractional CO2 laser for the treatment of Onychomycosis A single-center retrospective chart review was conducted during January 2015-December 2018. Patients, diagnosed with onychomycosis through fungal culture and/or potassium hydroxide staining, underwent three or more fractional CO2 laser treatments and used topical antifungal agents. Treatment effects were assessed by using clinical images at 6, 12 months, and the last visit. Ninety-six patients were included; they underwent an average of 7.7 laser treatment sessions. Finally, 15 patients (15.6%) showed complete response (100% clearing of all nails), 24 patients (25%) showed partial response, and 57 patients (59.4%) showed no response (no 100% clearing of nails among all treated toenails per patient including mild improvement or temporary cosmetic improvement). Multivariable logistic regression analysis revealed longer disease duration (p = 0.006, OR = 1.16 [95% CI: 1.05-1.31]), patients with diabetes (p = 0.021, OR = 9.82 [95% CI: 1.75-94.01]) and fewer number of laser treatment sessions (p = 0.001, OR = 0.76 [95% CI: 0.64-0.89]) were significantly associated with non-response group. In conclusion, fractional CO2 laser with topical antifungal could be a safe alternative treatment in patients with onychomycosis, who are difficult to take oral antifungals.

Rare Case of Double-Positive CD4/CD8 Immunophenotype in Lennert Lymphoma With Cutaneous Involvement: A Case Report.

ABSTRACT: Lennert lymphoma is a lymphoepithelioid variant of peripheral T-cell lymphoma (not otherwise specified) with characteristics that do not fit into other peripheral T-cell lymphoma categories. Lennert lymphoma is primarily a nodal disease, and skin involvement may be exhibited. Cutaneous manifestations in Lennert lymphoma are nonspecific and include erythematous papules, nodules, and small plaques. Histological examination of cutaneous involvement characteristically presents epithelioid histiocytes and atypical small lymphocytes around vessels or appendages. A lymph node (LN) biopsy is essential for Lennert lymphoma diagnosis. In Lennert lymphoma, immunohistochemistry of both LNs and the involved skin reveals T-cell marker positivity. Although most Lennert lymphoma cases present with a single-positive CD4/CD8 immunophenotype, few cases present with a double-positive CD4/CD8 immunophenotype. We report a case of a 54-year-old woman presenting with fever, chills, general weakness, and a skin rash of erythematous patches on the trunk, extremities, and buttocks. A skin biopsy of the buttocks revealed atypical lymphocytes around the dermal vessels. In immunohistochemistry, these atypical lymphocytes stained positive for CD3, CD4, CD8, and CD68 but negative for CD20, CD30, and granzyme B. Similarly, a biopsy of the axillary LN revealed numerous epithelioid cells with atypical lymphocytes, exhibiting positivity for CD3, CD4, CD8, and CD68 but negativity for CD20, CD30, and S-100. Ki-67 was overexpressed in both the skin and LN. The final diagnosis of the patient was Lennert lymphoma with cutaneous involvement and a rare double-positive CD4/CD8 immunophenotype. The patient was transferred to another hospital for chemotherapy as per her request.

Design and Synthesis of Conformationally Flexible Scaffold as Bitopic Ligands for Potent D3-Selective Antagonists.

Previous studies have confirmed that the binding of D3 receptor antagonists is competitively inhibited by endogenous dopamine despite excellent binding affinity for D3 receptors. This result urges the development of an alternative scaffold that is capable of competing with dopamine for binding to the D3 receptor. Herein, an SAR study was conducted on metoclopramide that incorporated a flexible scaffold for interaction with the secondary binding site of the D3 receptor. The alteration of benzamide substituents and secondary binding fragments with aryl carboxamides resulted in excellent D3 receptor affinities (Ki = 0.8-13.2 nM) with subtype selectivity to the D2 receptor ranging from 22- to 180-fold. The ß-arrestin recruitment assay revealed that 21c with 4-(pyridine-4-yl)benzamide can compete well against dopamine with the highest potency (IC50 = 1.3 nM). Computational studies demonstrated that the high potency of 21c and its analogs was the result of interactions with the secondary binding site of the D3 receptor. These compounds also displayed minimal effects for other GPCRs except moderate affinity for 5-HT3 receptors and TSPO. The results of this study revealed that a new class of selective D3 receptor antagonists should be useful in behavioral pharmacology studies and as lead compounds for PET radiotracer development.

Prognostic effects of cytokine levels on patients treated with taxane and zoledronic acid for metastatic breast cancer in bone (BEAT-ZO) (KCSG BR 10-13).

Advanced breast cancer frequently metastasizes to the skeleton causing major mobility issues and hazards to quality of life. To manage osteolytic bone metastasis, bone-modifying agents and chemotherapy are recommended as the standard of care. Here, we investigated serologic biomarkers that might be associated with prognosis in breast cancer patients treated with zoledronic acid (ZA) and taxane-based chemotherapy. We collected serum samples from breast cancer patients with bone metastasis who received taxane plus ZA as palliative treatment. Fourteen biomarkers of angiogenesis, immunogenicity, and apoptosis were assessed, and the correlation between serum cytokine levels and patient's prognosis was statistically analyzed. Sixty-six patients were enrolled, and samples from 40 patients were analyzed after laboratory quality control. Patients with low baseline PDGF-AA, high IFN-γ, low MCP-2, low TGF-ß1, and low TNF-α were significantly associated with longer progression-free survival (PFS). Decreasing VEGF and TNF-α and increasing FGF-2 and PDGF-AA in the early treatment phase indicated longer PFS. In univariate and multivariate analyses, low TGF-ß1 and TNF-α and high IFN-γ at baseline were associated with a significantly low hazard ratio for disease progression. Further, we designed a risk score with TGF-ß1, TNF-α, and IFN-γ levels, which could prognosticate patients for PFS. In conclusion, serum cytokine level, such as TGF-ß1, TNF-α, and IFN-γ, could be a potential prognostic biomarker for breast cancer patients with bone metastasis treated with ZA and taxane-based chemotherapy.

Agile reversible shape-morphing of particle rafts.

Materials that transform shapes responding to external stimuli can bring unprecedented innovations to soft matter physics, soft robotics, wearable electronics, and architecture. As most conventional soft actuation technologies induce large deformations only in a preprogrammed manner at designated locations, the material systems capable of agile reversible deformations without prescribed patterns are strongly desired for versatile mechanical morphing systems. Here we report a morphable liquid interface coated with dielectric particles, or a particle raft, which can reversibly change its topography under an external electric field. The rafts change from flat floors to towers within seconds, and the morphed structures are even capable of horizontal translation. Our experiments and theory show that the raft deformation is driven by electrostatic attraction between particles and electrodes, while being modulated by electric discharge. A broad range of materials serving as electrodes, e.g., human fingers and transparent polymers, suggests this system's diverse applications, including the human-machine interface and the three-dimensional physical display.

Coalescence of oil drops and films on micropillared substrates enabled by enhanced water drainage through pillar gaps.

Collecting or removing oil drops dispersed in water is essential in a range of industrial processes including oil recovery and oil spill cleanup. However, it is by no means easy to induce merging of oil drops with another body of oil due to slow drainage of the intervening water film. Here, we report immediate coalescence of oil drops with oil films that lie on micropillar arrays as immersed in various aqueous solutions. In addition to experimental demonstrations, we theoretically construct a regime map to predict whether the drop will bounce off or coalesce with the oil film, which is determined by the oil film thickness, geometry of the pillar array and liquid properties. Good agreement between theory and experiment indicates that micropillar arrays provide additional drainage paths of the intervening film, which helps drop-film coalescence. Our results suggest potential implications of utilizing oil-laden microporous structures to achieve efficient demulsification of oil drops in contaminated water.

Treatment and Outcomes of Metastatic Pancreatic Cancer in Elderly Patients.

BACKGROUND AND AIMS: Although pancreatic cancers are common in older age-groups, the prognosis remains poor due to limited studies on treatment approaches and outcomes in a given population. We aimed to examine treatment patterns and their outcomes in older patients with metastatic pancreatic cancer in a real-world context. MATERIALS AND METHODS: We conducted a retrospective study including 167 patients with metastatic pancreatic cancer (aged ≥70 years and male/female: 78/89) between January 2010 and July 2015. Patients' retrieved data from medical records were analyzed according to treatment types, followed by a review of clinicopathologic variables and treatment outcomes. RESULTS: Of the 167 eligible patients for the study, only 21.6% (n = 36) received palliative chemotherapy. The median age of the chemotherapy group was 74.0 years and 78.6 years for the supportive care group. The median survival of the chemotherapy group was 9.2 months (range: 1.0-24.9 months), compared with that of the supportive care group, which was 2.3 months (range: 0.1-31.8 months). Among the patients in the chemotherapy group, 50% (n = 18) received gemcitabine-based double therapy, and 30% patients (n = 9) received second-line chemotherapy. CONCLUSIONS: Our results showed that older patients with metastatic pancreatic cancer were less likely to receive chemotherapy. However, the survival benefit from chemotherapy was comparable to that of younger patients' counterpart. Thus, further study involving identification of older patients who would benefit from cytotoxic chemotherapy is needed.

A Case of Eosinophilic Pustular Folliculitis Associated With Herpes Zoster.

ABSTRACT: Patients with eosinophilic pustular folliculitis (EPF), a sterile eosinophilic infiltration of hair follicles, often present with papulopustules that tend to form annular plaques. Histopathologic examination revealed eosinophilic infiltration around the pilosebaceous units and eosinophilic microabscess formation. Although the pathogenesis of EPF is unknown, T-helper type 2 immune responses were suggested to be important based on their stimulating effect on the sebaceous glands. Here, we report the first case of EPF associated with herpes zoster, indicating that herpes zoster and EPF are correlated with T-helper type 2 immune responses.

Intermetallic PtCu Nanoframes as Efficient Oxygen Reduction Electrocatalysts.

Nanoframe alloy structures represent a class of high-performance catalysts for the oxygen reduction reaction (ORR), owing to their high active surface area, efficient molecular accessibility, and nanoconfinement effect. However, structural and chemical instabilities of nanoframes remain an important challenge. Here, we report the synthesis of PtCu nanoframes constructed with an atomically ordered intermetallic structure (O-PtCuNF/C) showing high ORR activity, durability, and chemical stability. We rationally designed the O-PtCuNF/C catalyst by combining theoretical composition predictions with a silica-coating-mediated synthesis. The O-PtCuNF/C combines intensified strain and ligand effects from the intermetallic PtCu L11 structure and advantages of the nanoframes, resulting in superior ORR activity to disordered alloy PtCu nanoframes (D-PtCuNF/C) and commercial Pt/C catalysts. Importantly, the O-PtCuNF/C showed the highest ORR mass activity among PtCu-based catalysts. Furthermore, the O-PtCuNF/C exhibited higher ORR durability and far less etching of constituent atoms than D-PtCuNF/C and Pt/C, attesting to the chemically stable nature of the intermetallic structure.