Exploratory Clinical Trial of a Depression Diagnostic Software That Integrates Stress Biomarkers and Composite Psychometrics.

OBJECTIVE: This study evaluated the clinical effectiveness of Minds.NAVI, a depression screening kit combining psychometric measures and stress hormone biomarkers, in a prospective clinical trial. The objective was to assess its potential as a depression screening tool and investigate the associations between psychological assessments, salivary hormone staging, and depression severity. METHODS: Thirty-five participants with major depressive disorder and 12 healthy controls (HCs) were included. The Minds.NAVI software, utilizing the PROtective and Vulnerable factors battEry Test (PROVE) and salivary cortisol/dehydroepiandrosterone (DHEA) analysis, was employed. The PROVE test is a comprehensive self-report questionnaire that assesses depressive symptoms, suicide risk, attachment style, adverse childhood experiences, mentalization capacity, and resilience. In addition, salivary cortisol and DHEA levels were measured to evaluate the functional stage of the hypothalamic-pituitary-adrenal (HPA) axis. RESULTS: Minds.NAVI exhibited 100% sensitivity, 91.7% specificity, and 97.9% accuracy in distinguishing depression from HCs within an exploratory small group. Salivary stress hormone phases showed changes with depression stage (p=0.030), and the proportion of patients with "adrenal exhaustion stage" was higher in the moderate/severe depression group (p=0.038). Protective/vulnerable factors differed significantly between controls and depressed groups (p<0.001). Cortisol awakening response inversely correlated with depressive symptom severity (r=-0.31, p=0.034). CONCLUSION: This study suggested possible clinical effectiveness of Minds.NAVI, a depression screening tool that integrates psychometric measures and stress hormone biomarkers. The findings support the potential association between depression, chronic stress, and HPA axis hyporesponsiveness.

Neurophysiological insights into impaired mentalization in borderline personality disorder an electroencephalography study.

Introduction: Borderline personality disorder (BPD) is characterized by interpersonal and emotional instabilities, recurring suicidal tendencies, and feelings of emptiness. Childhood adverse event is reported in 70%-80% of cases involving BPD. Furthermore, the deficiency in mentalization capacity plays a significant role in emotion dysregulation and social interaction problems within individuals with BPD. This study explored the relationship among childhood adverse experiences, mentalization capacity, and neurophysiological activity in patients with BPD. Methods: Resting-state electroencephalography was used to identify the neural correlates associated with childhood adversity and mentalization deficits. The participants included 45 patients with BPD and 15 healthy controls. Results: The BPD group exhibited reduced alpha activity during eyes-closed rest, indicating heightened arousal even during relaxation. Correlations were found between the power spectral density (PSD) and mentalization capacity in the delta and theta ranges, suggesting an association between PSD and emotional awareness and expression. Gamma activity negatively correlated with psychic equivalence, implying a blurring of the boundaries between internal mental experiences and the external world. Conclusion: These findings offer insights into the pathophysiology of BPD, provide potential diagnostic markers, and suggest personalized treatment approaches based on mentalization traits.

Relationship of Resilience Factors With Biopsychosocial Markers Using a Comprehensive Home Evaluation Kit for Depression and Suicide Risk: A Real-World Data Analysis.

Objectives: Adverse childhood experiences (ACEs) are fundamental factors in developing depression with increased suicide risk. Resilience is considered an important protective factor that can prevent trauma survivors from developing depression. We developed a home evaluation kit for a comprehensive assessment of bio-psycho-social factors related to depression and suicide. This kit contained a psycho-social evaluation battery, named the Protective and Vulnerable factors battery questionnaire (PROVE) comprising depressive symptoms and suicide risk, as well as various depression-related psychosocial factors, such as ACE, resilience, mentalization capacity, and attachment, via online survey tools. Furthermore, salivary cortisol levels were used as biological indicators to assess the hypothalamus-pituitary-adrenal axis function. Methods: Real-world data analysis was made out of data collected from participants who visited CHEEU Counseling center or Gangnam Severance hospital for mental health check-ups. The participants were put into three mental state groups (green-normal, yellow-borderline, and red-risk) depending on the result of PROVE battery. The difference between psychosocial factors and salivary cortisol indicators by the group was identified by analysis of covariance with sex and age as covariates. Linear regression analysis was conducted to find a significant association of resilience score with other bio-psycho-social variables, such as ACE, attachment, mentalization, or post-awakening cortisol concentrations (area under the curve with respect to ground, AUCg). A partial correlation analysis was performed to evaluate the relationship of AUCg with psychosocial factors. Results: Depression-related psycho-social indicators were significantly different among groups. Insecure attachment and the mentalization problem are negatively influencing factors to resilience. Furthermore, the severity of depression in participants with ACE was also influenced by mentalization problems. AUCg was different according to the PROVE group, presence of ACE, or resilience level. In addition, AUCg showed a positive correlation with resilience score but negative correlations with depressive symptoms, ACE, mentalization problems, and anxiety or avoidance attachment. Conclusion: This study suggests that there are some key factors negatively affecting resilience: insecure attachment and mentalization problems. In groups with ACE, a mentalization problem was suggested as a factor that can increase depressive symptoms. AUCg was associated with resilience as well as several other vulnerable factors of depression, showing its potential as a promising biomarker.

Effects of Sophorolipid on Growth Performance, Organ Characteristics, Lipid Digestion Markers, and Gut Functionality and Integrity in Broiler Chickens.

Dietary fat and oil could aid in reaching the high-energy requirements of fast-growing birds; however, these inclusions could lead to nutrient waste. This is because young birds have limited lipid digestion due to the low secretion of lipase and bile salt. Sophorolipid (SPL), a glycolipid emulsifier with lower toxicity and higher biodegradability, can upregulate fat utilization by increasing digestibility. Accordingly, a five-week-long experiment was conducted with 720 one-day-old chicks (Ross 308) to investigate the effects of dietary SPL on growth, organ characteristics, and gut health. The allotment was partitioned into four treatment groups according to their body weight with six replications (30 chick/pen). The three treatment diets comprised a basal diet with a formulation that met the Ross 308 standard and 5, 10, and 15 ppm SPL in the basal diet. During the experiment, the birds had free access to feed, and body weight and feed intake were measured at the end of each phase. Chickens were put down at the end of the growing and finishing phases, and jejunum and cecal samples were obtained to investigate organ characteristics and gut environments. The data were analyzed using the generalized linear model procedures of SAS 9.4, and all data were assessed for linear, quadratic, and cubic effects of dietary SPL-supplemented dosages. Body weight was significantly increased with 10 ppm of SPL supplementation in the grower phase without affecting feed efficiency. The relative weights of the intestine and the bursa of Fabricius were quadratically decreased by SPL supplementation with a lower population of Streptococcus and higher propionate and butyrate concentrations. Additionally, the dietary SPL supplementation groups showed a significantly increased villus/crypt ratio with higher intestinal expression levels of fatty acid translocase, diacylglycerol acyltransferase 2, and fatty acid transporter 4. Collectively, proper SPL supplementation in the chicken diet could improve growth performance by down-regulating immune modulation and up-regulating lipid digestion and absorption via modulation of gut microenvironments.

Two-Dimensional calcium silicate nanosheets for trapping atmospheric water molecules in humidity-immune gas sensors.

In humid conditions, water vapor can easily neutralize the surface active sites of metal oxide sensors, leading to a lowering in the sensitivity of the gas sensor and a resultant inaccurate signal in practical applications. Herein, we present a new hybrid sensor by introducing a two-dimensional calcium silicate (CS) nanosheet as a water-trapping layer in SnO2 nanowires. Unlike the heavily wrinkled and aggregated morphology of conventional CS nanosheets, our nanosheet in the hybrid material is ultrathin and flat. Moreover, it was grown in the empty spaces between the spider-web-like networks of SnO2 nanowires without covering the nanowire surface. These two morphological features improve moisture trapping with minimal reduction in the active sensing area. Consequently, stable and sensitive gas detection under humid conditions was achieved in this hybrid sensor. The superior humidity-independent sensing is ascribed to the preferential adsorption of water molecules on hydroscopic CS nanosheets through the hydrogen bond. Based on density functional theory calculations, we determined that the improved gas response is driven by the additional formation of oxygen vacancy in SnO2 due to the diffusion of aliovalent Ca ions from the CS nanosheet.

Sophorolipid protects against early-weaning syndrome by improving the gut microenvironment in early-weaned piglets.

BACKGROUND: In animals, weaning stress is the first and most critical stress. Weaning can negatively affect the growth performance of animals physically, psychologically, and pathologically. Our previous studies on the HT-29 cell line and early-weaned rats demonstrated that adequate sophorolipid (SPL) supplementation in feed could enhance the mucin-producing and wound healing capacities of the gut defense system by modulating gut microbiota. METHODS: We conducted an experiment with one hundred forty 21-day-old early weaned piglets (L x Y x D). They were allocated into 4 treatment and 7 replications (4 pigs per pen) according to their initial body weight. Body weight and feed intake were measured biweekly during experimental period. After 6 weeks, 28 pigs were randomly selected and sacrificed to collect plasma, jejunum, and cecal content samples. RESULTS: Dietary SPL supplementation at 5 and 10 mg/kg quadratically increased the average daily gain during the experimental period in the treatment groups when compared with the control group. The albumin levels of piglets fed with the SPL supplemented diet were downregulated to the normal range. Moreover, in feed, SPL supplementation at 5 and 10 mg/kg improved jejunal histological indices and gene expression levels related to mucin secretion and local inflammation markers. Consistent with these results, adequate SPL supplementation (5 and 10 mg/kg) increased the population of Prevotella, a beneficial bacterium, and its short-chain fatty acid production in the ceca of piglets. CONCLUSIONS: The occurrence of diarrhea after weaning in piglets could be reduced by feeding a 10 ppm of SPL supplemented diet which improves the gut defense system by improving the microbial population and enhancing mucin layer integrity.

Virtual reality-based monitoring test for MCI: A multicenter feasibility study.

Objectives: As the significance of the early diagnosis of mild cognitive impairment (MCI) has emerged, it is necessary to develop corresponding screening tools with high ecological validity and feasible biomarkers. Virtual reality (VR)-based cognitive assessment program, which is close to the daily life of the older adults, can be suitable screening tools for MCI with ecological validity and accessibility. Meanwhile, dehydroepiandrosterone (DHEA) has been observed at a low concentration in the older adults with dementia or cognitive decline, indicating its potential as a biomarker of MCI. This study aimed to determine the efficacy and usability of a VR cognitive assessment program and salivary DHEA for screening MCI. Methods: The VR cognitive assessment program and the traditional Montreal Cognitive Assessment (MOCA) test were performed on 12 patients with MCI and 108 healthy older adults. The VR program operates in a situation of caring for a grandchild, and evaluates the memory, attention, visuospatial, and executive functions. An analysis of covariance (ANCOVA), a partial correlation analysis, and receiving operating characteristic (ROC) curve analysis were conducted for statistical analysis. Results: According to the ANCOVA, no significant difference in MOCA scores was found between the normal and MCI groups (F = 2.36, p = 0.127). However, the VR total score of the MCI group was significantly lower than that of the normal group (F = 8.674, p = 0.004). There was a significant correlation between the MOCA and VR scores in the total and matched subdomain scores. The ROC curve analysis also showed a larger area under the curve (AUC) for the VR test (0.765) than for the MOCA test (0.598), and the sensitivity and specificity of the VR program were 0.833 and 0.722, respectively. Salivary DHEA was correlated with VR total (R 2 = 0.082, p = 0.01) and attention scores (R 2 = 0.086, p = 0.009). Conclusion: The VR cognitive test was as effective as the traditional MOCA test in the MCI classification and safe enough for older adults to perform, indicating its potential as a diagnostic tool. It has also been shown that salivary DHEA can be used as a biomarker for MCI.

Comparison of the Outcomes of Percutaneous Endoscopic Interlaminar Lumbar Discectomy and Open Lumbar Microdiscectomy at the L5-S1 Level.

BACKGROUND: Although many studies have compared full endoscopic spine surgery and open spine surgery, few have compared the outcomes of percutaneous endoscopic interlaminar lumbar discectomy (PEILD) and open lumbar microdiscectomy (OLM) at the L5-S1 level. OBJECTIVES: We compared the clinical, surgical, and radiological outcomes of patients with disc herniation at the L5-S1 level who underwent either PEILD, or OLM, performed by a single surgeon with novice-level proficiency. STUDY DESIGN: Observational, retrospective matched cohort design. SETTING: An analysis of clinical data was performed at a single center, collected from September 2012 to August 2016. METHODS: The study enrolled 56 patients who underwent discectomy at the L5-S1 level, with a minimum one-year follow-up. Patients were allocated to 2 groups: a PEILD group (n = 27; September 2014 to August 2016), or an OLM group (n = 29; September 2012 to August 2014). Clinical, surgical, and radiological outcomes were retrospectively evaluated. RESULTS: Baseline characteristics including age, gender, past medical history, body mass index, preoperative symptom, and preoperative radiological findings did not differ significantly between the groups. Further, overall clinical outcomes including back and leg pain; surgical outcomes including blood loss, complication rate, and recurrence rate; and radiological outcomes including degree of decompression, disc height, and sagittal alignment were not different significantly between the 2 groups.However, the PEILD group showed significant advantages including lower immediate postoperative back pain (mean 1.44 [95% confidence interval (CI), 1.16-1.72] versus 2.41 [95% CI, 2.14-2.69], P < 0.001), favorable immediate postoperative Odom's criteria (excellent 57.14% versus 24.14%, P = 0.025), shorter operation time (mean 63.89 ±17.99 minutes versus 109.66 ±31.42 minutes, P < 0.001), shorter hospital stay (3.15 [95% CI, 2.21-4.09] days versus 5.72 [95% CI, 3.29-8.16] days, P < 0.001), and rapid return to work (15.67 [95% CI, 12.64-18.69] days versus 24.31 [95% CI ,19.97-28.65] days, P = 0.001). LIMITATION: Due to its retrospective nature, it was not possible to control for all variations. Moreover, the number of patients in the final cohort was relatively small. CONCLUSIONS: Our findings indicate that the PEILD group achieved better perioperative outcomes despite no significant intergroup difference in mid-term clinical and radiological outcomes.

Rapid Symptom Improvement in Major Depressive Disorder Using Accelerated Repetitive Transcranial Magnetic Stimulation.

OBJECTIVE: Repetitive transcranial magnetic stimulation (rTMS) has contributed to increase in the remission rate for patients with major depressive disorder (MDD). However, current rTMS treatment is practically inconvenient because it requires daily treatment sessions for several weeks. Accelerated rTMS treatment is as efficient and safe for MDD patients as conventional rTMS. METHODS: Fifty-one patients with MDD participated in this study; they were randomized into accelerated rTMS (n = 21), conventional rTMS (n = 22), and sham-treatment (n = 8) groups. The accelerated and conventional rTMS groups received 15 sessions for 3 days and 3 weeks, respectively. The sham-treatment group received 15 sham rTMS sessions for 3 days. Primary outcome was assessed using self-report and clinician-rated Korean Quick Inventory of Depressive Symptomatology (KQIDS-SR and KQIDS-C, respectively). Adverse effects were monitored using the Frequency, Intensity, and Burden of Side Effects Rating scale. Changes in depressive symptoms were compared among the three groups using mixed model analyses. RESULTS: For the KQIDS-SR score, there was a significant main effect of "time" (F3,47 = 11.05, p < 0.001), but no effect of "group" (F2,47 = 2.04, p = 0.142), and a trend-level interaction effect of "group × time" (F6,47 = 2.26, p = 0.053). Improvement in depressive symptoms, based on the KQIDS-SR score 3 weeks after treatment, was more prominent in the accelerated rTMS group than in the sham-treatment group (p = 0.011). Tolerability was comparable among the three groups. CONCLUSION: The accelerated rTMS treatment group showed rapid improvement of depressive symptoms compared with the sham-treatment and conventional rTMS treatment groups. Therefore, accelerated rTMS treatment could be a viable option for MDD, with improved accessibility.

Interface treatment using amorphous-carbon and its applications.

Breakthrough process technologies have been introduced that can increase the chemical sensitivity of an interface at which reactions occur without significantly altering the physico-chemical properties of the material. Such an interfacial treatment method is based on amorphous-carbon as a base so that fluids can be deposited, and the desired thickness and quality of the deposition can be ensured irrespective of the interface state of the material. In addition, side effects such as diffusion and decreasing strength at the interface can be avoided. This is simpler than existing vacuum-based deposition technology and it has an unmatched industrial advantage in terms of economics, speed, accuracy, reliability, accessibility, and convenience. In particular, this amorphous-carbon interface treatment technology has been demonstrated to improve gas-sensing characteristics of NO2 at room temperature.

Synthesis of Au/SnO2 nanostructures allowing process variable control.

Theoretical advances in science are inherently time-consuming to realise in engineering, since their practical application is hindered by the inability to follow the theoretical essence. Herein, we propose a new method to freely control the time, cost, and process variables in the fabrication of a hybrid featuring Au nanoparticles on a pre-formed SnO2 nanostructure. The above advantages, which were divided into six categories, are proven to be superior to those achieved elsewhere, and the obtained results are found to be applicable to the synthesis and functionalisation of other nanostructures. Furthermore, the reduction of the time-gap between science and engineering is expected to promote the practical applications of numerous scientific theories.

ZnO Nanocluster-Functionalized Single-Walled Carbon Nanotubes Synthesized by Microwave Irradiation for Highly Sensitive NO2 Detection at Room Temperature.

To improve the NO2-sensing performance of single-walled carbon nanotube (SWCNT)-based sensors, zinc oxide (ZnO) nanoclusters (NCs) were functionalized by a microwave (MW)-assisted synthesis technique. Gas sensors based on pristine SWCNTs and ZnO NC-SWCNT composites synthesized using different weight ratios (ZnO/SWCNTs = 0.5:1, 1:1, 2:1, and 3:1) were fabricated, and their ability to sense various gases at room temperature (25 °C) was investigated. The results showed that the sensing performance of the ZnO NC-SWCNT composite synthesized with a weight ratio of 1:1 (denoted as Z-SWCNTs) was significantly enhanced with respect to NO2 response and selectivity. This enhanced sensing performance is thought to be a result of both the modulation of the conduction channel at the ZnO NC-SWCNT heterointerfaces and the generation of defects (or holes) by MW irradiation that act as active sites for the target gases. The results obtained in this work provide not only a facile method of cofunctionalizing oxide NCs and defects but also a new methodology for improving the sensing capabilities of SWCNT-based gas sensors.

Fast Semiconductor-Metal Bidirectional Transition by Flame Chemical Vapor Deposition.

A simple yet powerful flame chemical vapor deposition technique is proposed that allows free control of the surface morphology, microstructure, and composition of existing materials with regard to various functionalities within a short process time (in seconds) at room temperature and atmospheric pressure as per the requirement. Since the heat energy is directly transferred to the material surface, the redox periodically converges to the energy dynamic equilibrium depending on the energy injection time; therefore, bidirectional transition between the semiconductor/metal is optionally available. To demonstrate this, a variety of Sn-based particles were created on preformed SnO2 nanowires, and this has been interpreted as a new mechanism for the response and response times of gas-sensing, which are representative indicators of the most surface-sensitive applications and show one-to-one correspondence between theoretical and experimental results. The detailed technologies derived herein are clearly influential in both research and industry.

New type of doping effect via metallization of surface reduction in SnO2.

The use of conventional doping methods requires consideration of not only the energy connection with the base material but also the limits of the type and doping range of the dopant. The scope of the physico-chemical change must be determined from the properties of the base material, and when this limit is exceeded, a large energy barrier must be formed between the base material and the dopant as in a heterojunction. Thus, starting from a different viewpoint, we introduce a so-called metallization of surface reduction method, which easily overcomes the disadvantages of existing methods while having the effect of doping the base material. Such new synthetic techniques enable sequential energy arrangements-gradients from the surface to the centre of the material-so that free energy transfer effects can be obtained as per the energies in the semiconducting band, eliminating the energy discontinuity of the heterojunction.

Preliminary Findings on the Effectiveness of Meaning-Centered Psychotherapy in Patients with Pancreatobiliary Cancer.

PURPOSE: This study investigated the effectiveness of meaning-centered psychotherapy (MCP), which is known to be a helpful psychotherapeutic intervention in distressing conditions, for patients with pancreatobiliary cancer. MATERIALS AND METHODS: We recruited 37 patients with pancreatobiliary cancer from three university general hospitals and assessed their psychological characteristics. Patients who reported clinically significant emotional distress were recommended to undergo MCP. Patients who consented to MCP were provided four sessions of the therapy. Patient psychological characteristics were assessed again 2 months after MCP. For statistical comparison, outcome variables included anxiety, depression, mental adjustment to cancer, and quality of life (QoL), as well as the degree of stress and physical symptoms. RESULTS: Sixteen patients completed the MCP and the final assessment 2 months later. In the initial assessment, the patients receiving MCP showed higher levels of anxiety and depression than those not receiving MCP, and QoL was also lower in terms of role function, emotional function, social function, and global QoL. At the 2-month follow-up, the MCP group showed a significant improvement in anxiety (p=0.007), depression (p=0.010), and anxious preoccupation (p<0.001). In addition, QoL significantly improved in the MCP group, while there was no significant change in the non-MCP group. CONCLUSION: In this study, MCP showed potential therapeutic benefits against emotional distress in patients with pancreatobiliary cancer, improving their QoL.

Early life stress, resilience and emotional dysregulation in major depressive disorder with comorbid borderline personality disorder.

BACKGROUND: Borderline personality disorder (BPD) show different course and treatment compared to major depressive disorder (MDD). Early life stress may increase BPD onset; however, resilience may play a protective role against the development of psychopathology. The goal of this study was to compare the early life stress, resilience, and the clinical characteristics of emotional dysregulation in patients with MDD with and without comorbid BPD. METHODS: Thirty patients with both BPD and MDD, 25 patients with MDD alone, and 25 age- and sex- matched healthy controls, participated in this study. Analysis of variance was used to compare the early life stress, resilience, and emotional dysregulation among groups. Also, multivariate logistic regression models were used to identify the relationship of the early life stress and resilience domains with BPD comorbidity within MDD patients. RESULTS: The domains of emotional abuse and self-regulation ability were significantly associated with BPD comorbidity and BPD severity. In emotional dysregulation, difficulty scores of impulsivity, coping strategies, and emotion clarity domains were significantly increased in patients with both BPD and MDD compared to patients with MDD alone. LIMITATIONS: The relatively small sample size may contribute to reduce statistical power of investigation. CONCLUSIONS: Emotional abuse experiences in early life, and deficits in self-regulation, are significantly associated with comorbid BPD in patients with MDD. A comprehensive evaluation including early life stress, resilience and emotion regulation ability may help to identify comorbid BPD in patients with MDD and develop treatment strategies.

Design and synthesis of amorphous SiOx structures generated by Sn quantum dots: growth mechanism and luminescent origin.

SiOx structures with different diameters of a few hundreds of nanometers and/or a few micrometers are prepared using applied thermal evaporation. Subsequently, Sn quantum dot-based SiOx architectures are synthesized via the continuous steps of the carbothermal reduction of SnO2, substitution of Sn(4+) for In(3+), thermal oxidation of Si, Sn sublimation, interfacial reaction, and diffusion reaction consistent with corresponding phase equilibriums. Several crystalline and spherical-shaped Sn quantum dots with diameters between 2 and 7 nm are observed in the amorphous SiOx structures. The morphological evolution, including hollow Sn (or SnOx) sphere and wire-like, worm-like, tube-like, and flower-like SiOx, occurs stepwise on the Si substrate upon increasing the given process energies. The optical characteristics based on confocal measurements reveal the as-synthesized SiOx structures, irrespective of whether crystallinity is formed, which all have visible-range emissions originating from the numerous different-sized and -shaped Sn quantum dots permeating into the SiOx matrix. In addition, photoluminescence emissions ranging between ultraviolet and red regions are in agreement with confocal measurements. The origins of the morphology- and luminescence-controlled amorphous SiOx with Sn quantum dots are also discussed.

Growth Mechanism and Luminescent Properties of Amorphous SiOx Structures via Phase Equilibrium in Binary System.

Balloon whisk-like and flower-like SiOx tubes with well-dispersed Sn and joining countless SiOx loops together induce intense luminescence characteristics in substrate materials. Our synthetic technique called "direct substrate growth" is based on pre-contamination of the surroundings without the intended catalyst and source powders. The kind of supporting material and pressure of the inlet gases determine a series of differently functionalized tube loops, i.e., the number, length, thickness, and cylindrical profile. SiOx tube loops commonly twist and split to best suppress the total energy. Photoluminescence and confocal laser measurements based on quantum confinement effect of the embedded Sn nanoparticles in the SiOx tube found substantially intense emissions throughout the visible range. These new concepts related to the synthetic approach, pre-pollution, transitional morphology, and permeable nanoparticles should facilitate progress in nanoscience with regard to tuning the dimensions of micro-/nanostructure preparations and the functionalization of customized applications.

Low Temperature Sensing Properties of Pt Nanoparticle-Functionalized Networked ZnO Nanowires.

Networked ZnO nanowires were fabricated via a vapor-phase selective growth method. Pt nanoparticles were functionalized on the networked ZnO nanowires. In this study, for the functioanlization, γ-ray radiolysis was applied. By the method, Pt nanoparticles of - 10 nm in diameter were uniformly anchored on the surface of each ZnO nanowire. The sensing properties of the Pt-functionalized, networked ZnO nanowires were investigated in terms of NO2, CO and benzene at 100 degrees C. The sensing capability of the Pt-functionalized ZnO nanowires at that temperature supports their potential use in chemical gas sensors.

Extraordinary improvement of gas-sensing performances in SnO2 nanofibers due to creation of local p-n heterojunctions by loading reduced graphene oxide nanosheets.

We propose a novel approach to improve the gas-sensing properties of n-type nanofibers (NFs) that involves creation of local p-n heterojunctions with p-type reduced graphene oxide (RGO) nanosheets (NSs). This work investigates the sensing behaviors of n-SnO2 NFs loaded with p-RGO NSs as a model system. n-SnO2 NFs demonstrated greatly improved gas-sensing performances when loaded with an optimized amount of p-RGO NSs. Loading an optimized amount of RGOs resulted in a 20-fold higher sensor response than that of pristine SnO2 NFs. The sensing mechanism of monolithic SnO2 NFs is based on the joint effects of modulation of the potential barrier at nanograin boundaries and radial modulation of the electron-depletion layer. In addition to the sensing mechanisms described above, enhanced sensing was obtained for p-RGO NS-loaded SnO2 NFs due to creation of local p-n heterojunctions, which not only provided a potential barrier, but also functioned as a local electron absorption reservoir. These mechanisms markedly increased the resistance of SnO2 NFs, and were the origin of intensified resistance modulation during interaction of analyte gases with preadsorbed oxygen species or with the surfaces and grain boundaries of NFs. The approach used in this work can be used to fabricate sensitive gas sensors based on n-type NFs.