Size-Dependent Isovalent Impurity Doping for Ambipolar Control in Cu3N.

Substitutional doping, involving the replacement of a host with an aliovalent impurity ion, is widely used to attain ambipolar controllability in semiconductors, which is crucial for device application. However, its effectiveness for p-type doping is limited in monovalent cation compounds due to the lack of suitable aliovalent (i.e., zerovalent) impurities. We propose an alternative approach for p- and n-type doping, mediated by the sizes of isovalent alkali metal impurities in Cu(I)-based semiconductors, such as copper nitride with an electron concentration of ∼1015 cm-3. Doping of isovalent Li with a smaller size to interstitial positions improves n-type conductivity, and electron concentration is controllable in the range of 1015 to 1018 cm-3. In contrast, larger isovalent Cs and Rb impurities facilitate p-type conversion, resulting in a hole concentration controllability of 1014 to 1017 cm-3. First-principles calculations indicate that Li is placed as an interstitial impurity acting as a shallow donor in conjunction with the formation of a neutral impurity on Cu defects. As the impurity size increases beyond the capacity of the vacant space, the formation of multiple acceptor-type Cu vacancies is enhanced owing to the repulsion between host Cu+ and Cs+/Rb+ impurities. Consequently, the Cs or Rb impurity is located at the sites of the N accompanied by six neighboring Cu vacancies, forming acceptor defect complexes. This size-dependent isovalent impurity doping scheme opens up an alternative avenue for advancement in optoelectronic devices using monovalent cation-based semiconductors.

Familial Adenomatous Polyposis with Atypical Clinical Morphology and Genetic Variants.

Familial adenomatous polyposis (FAP) is caused by pathogenic variants of the APC gene on the long arm of chromosome 5. An analysis showed an association between germline APC gene variants and clinical signs of FAP; however, attenuated FAP has also been reported in cases with pathogenic variants. In contrast, a phenotype of FAP with no APC germline pathogenic variant and with few signs has been reported. We herein report a 16-year-old girl in whom the presence of multiple large bowel cancers from a young age and several small bowel cancers reflected a carcinogenic tendency higher than that typical for FAP.

Understanding Colloidal Quantum Dot Device Characteristics with a Physical Model.

Colloidal quantum dots (CQDs) are finding increasing applications in optoelectronic devices, such as photodetectors and solar cells, because of their high material quality, unique and attractive properties, and process flexibility without the constraints of lattice match and thermal budget. However, there is no adequate device model for colloidal quantum dot heterojunctions, and the popular Shockley-Quiesser diode model does not capture the underlying physics of CQD junctions. Here, we develop a compact, easy-to-use model for CQD devices rooted in physics. We show how quantum dot properties, QD ligand binding, and the heterointerface between quantum dots and the electron transport layer (ETL) affect device behaviors. We also show that the model can be simplified to a Shockley-like equation with analytical approximate expressions for reverse saturation current, ideality factor, and quantum efficiency. Our model agrees well with the experiment and can be used to describe and optimize CQD device performance.

Serum leucine-rich alpha-2 glycoprotein in monitoring disease activity and intestinal mucosal healing for biotherapy-naïve cases with ulcerative colitis.

Background and Aim: Serum leucine-rich alpha-2 glycoprotein level has been reported to be a useful biomarker in assessing mucosal healing in patients undergoing biotherapy, where mucosal lesions caused by ulcerative colitis are difficult to assess endoscopically. However, no such reports have been reported in biotherapy-naïve cases. Methods: Sixty-eight patients with ulcerative colitis (UC) who were biotherapy-naïve at Kindai University Hospital between October 2021 and October 2022 were enrolled. We prospectively examined the correlation between leucine-rich alpha-2 glycoprotein (LRG), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and Geboes scores with clinical endoscopic activity using the Mayo endoscopic subscore (MES). Results: Mucosal healing was achieved in 39 (57%) patients. Univariate analysis revealed that the factors associated with mucosal healing were LRG (P = 0.0024), CRP (P = 0.1078), ESR (P = 0.0372), and Geboes scores (P = 0.0075). Logistic regression analysis identified LRG and Geboes scores as independent factors associated with mucosal healing assessed using MES (P = 0.0431 for LRG and P = 0.0166 for Geboes scores). Conclusion: LRG was found to be the easiest marker to monitor disease activity and mucosal inflammation in UC patients with biotherapy-naïve cases, with a performance equivalent to that of Geboes scores.

Hole-Doping to a Cu(I)-Based Semiconductor with an Isovalent Cation: Utilizing a Complex Defect as a Shallow Acceptor.

p-Type doping in Cu(I)-based semiconductors is pivotal for solar cell photoabsorbers and hole transport materials to improve the device performance. Impurity doping is a fundamental technology to overcome the intrinsic limits of hole concentration controlled by native defects. Here, we report that alkali metal impurities are prominent p-type dopants for the Cu(I)-based cation-deficient hole conductors. When the size mismatch with Cu+ in the host lattice is increased, these isovalent impurities are preferentially located at interstitial positions to interact with the constituent Cu cations, forming stable impurity-defect complexes. We demonstrate that the Cs impurity in γ-CuI semiconductors enhances hole concentration controllability for single crystals and thin films in the range of 1013-1019 cm-3. First-principles calculations indicate that the Cs impurity forms impurity-defect complexes that act as shallow acceptors leading to the increased p-type conductivity. This isovalent doping provides an approach for controlled doping into cation-deficient semiconductors through an interaction of impurities with native defects.

Reconfigurable Artificial Synapses with Excitatory and Inhibitory Response Enabled by an Ambipolar Oxide Thin-Film Transistor.

A gate-tunable synaptic device controlling dynamically reconfigurable excitatory and inhibitory synaptic responses, which can emulate the fundamental synaptic responses for developing diverse functionalities of the biological nervous system, was developed using ambipolar oxide semiconductor thin-film transistors (TFTs). Since the balanced ambipolarity is significant, a boron-incorporated SnO (SnO:B) oxide semiconductor channel was newly developed to improve the ambipolar charge transports by reducing the subgap defect density, which was reduced to less than 1017 cm-3. The ambipolar SnO:B-TFT could be fabricated with a good reproductivity at the maximum process temperature of 250 °C and exhibited good TFT performances, such as a nearly zero switching voltage, the saturation mobility of ∼1.3 cm2 V-1 s-1, s-value of ∼1.1 V decade-1, and an on/off-current ratio of ∼8 × 103 for the p-channel mode, while ∼0.14 cm2 V-1 s-1, ∼2.2 V decade-1and ∼1 × 103 for n-channel modes, respectively. The ambipolar device imitated potentiation/depression behaviors in both excitatory and inhibitory synaptic responses by using the p- and n-channel transports by tuning a gate bias. The low-power consumptions of <20 and <2 nJ per pulse for the excitatory and inhibitory operations, respectively, were also achieved. The presented device operated under an ambient atmosphere and confirmed a good operation reliability over 5000 pulses and a long-term air environmental stability. The study presents the high potential of an ambipolar oxide-TFT-based synaptic device with a good manufacturability to develop emerging neuromorphic perception and computing hardware for next-generation artificial intelligence systems.

Vacuum-Free Liquid-Metal-Printed 2D Indium-Tin Oxide Thin-Film Transistor for Oxide Inverters.

A cost-effective, vacuum-free, liquid-metal-printed two-dimensional (2D) (∼1.9 nm-thick) tin-doped indium oxide (ITO) thin-film transistor (TFT) was developed at the maximum process temperature of 200 °C. A large-sized 2D-ITO channel layer with an electron density of ∼1.2 × 1019 cm-3 was prepared in an ambient atmosphere. The 2D-ITO-TFT operated in full depletion with a threshold voltage of -2.1 V and demonstrated good TFT device characteristics such as a high saturation mobility of ∼27 cm2 V-1 s-1, a small subthreshold slope of <382 mV decade-1, and a large on/off-current ratio of >109. The TFT device simulation analysis found that the 2D-ITO-TFT performances were controlled by the shallow acceptor-like in-gap defects spreading in the midgap region of over 1.0 eV below the conduction band minimum. Post-thermal annealing tuned the electron density of the 2D-ITO channel and enabled it to produce enhancement and depletion-mode 2D-ITO-TFTs. A full signal swing zero-VGS-load n-type metal-oxide semiconductor (NMOS) inverter composed of depletion-load/enhancement-driver 2D-ITO-TFTs and a complementary inverter with p-channel 2D-SnO-TFT were successfully demonstrated using all 2D-oxide-TFTs.

Atomically Thin Tin Monoxide-Based p-Channel Thin-Film Transistor and a Low-Power Complementary Inverter.

Atomically thin oxide semiconductors are significantly expected for next-generation cost-effective, energy-efficient electronics. A high-performance p-channel oxide thin-film transistor (TFT) was developed using an atomically thin p-type tin monoxide, SnO channel with a thickness of ∼1 nm, which was grown by a vacuum-free, solvent-free, metal-liquid printing process at low temperatures, as low as 250 °C in an ambient atmosphere. By performing oxygen-vacancy defect termination for the bulk-channel and back-channel surface of the ultrathin SnO channel, the presented p-channel SnO TFT exhibited good device performances with a reasonable TFT mobility of ∼0.47 cm2 V-1 s-1, a high on/off current ratio of ∼106, low off current of <10-12 A, and a subthreshold swing of ∼2.5 V decade-1, which was improved compared with the conventional p-channel SnO TFTs. We also fabricated metal-liquid printing-based n-channel oxide TFTs such as n-channel SnO2 and In2O3-TFTs and developed ultrathin-channel oxide-TFT-based low-power complementary inverter circuits with the developed p-channel SnO TFTs. The full swing of voltage-transfer characteristics with a voltage gain of ∼10 and a power dissipation of <4 nW for p-SnO/n-SnO2 and ∼120 and <2 nW for p-SnO/n-In2O3-CMOS inverters were successfully demonstrated.

Artificial Synapse Based on a 2D-SnO2 Memtransistor with Dynamically Tunable Analog Switching for Neuromorphic Computing.

A new type of two-dimensional (2D) SnO2 semiconductor-based gate-tunable memristor, that is, a memtransistor, an integrated device of a memristor and a transistor, was demonstrated to advance next-generation neuromorphic computing technology. The polycrystalline 2D-SnO2 memristors derived from a low-temperature and vacuum-free liquid metal process offer several interesting resistive switching properties such as excellent digital/analog resistive switching, multistate storage, and gate-tunability function of resistance switching states. Significantly, the gate tunability function that is not achievable in conventional two-terminal memristors provides the capability to implement heterosynaptic analog switching by regulating gate bias for enabling complex neuromorphic learning. We successfully demonstrated that the gate-tunable synaptic device dynamically modulated the analog switching behavior with good linearity and an improved conductance change ratio for high recognition accuracy learning. The presented gate-tunable 2D-oxide memtransistor will advance neuromorphic device technology and open up new opportunities to design learning schemes with an extra degree of freedom.

Back-Channel Defect Termination by Sulfur for p-Channel Cu2O Thin-Film Transistors.

The absence of a high-performance p-channel oxide thin-film transistor (TFT) is the major challenge faced in the current oxide semiconductor device technology. Simple solution-based back-channel subgap defect termination using sulfur was developed for p-channel cuprous oxide (Cu2O)-TFTs. We investigated the origin of poor device characteristics in conventional Cu2O-TFTs and clarified that it was mainly because of a back-channel donor-like defect of ∼2.8 ×1013 cm-2 eV-1, which originated from the interstitial Cu defect. Sulfur ion treatment using thiourea effectively reduced the back-channel defect down to <3 × 1012 cm-2 eV-1 and demonstrated the Cu2O-TFT with a saturation mobility of 1.38 ± 0.7 cm2 V-1 s-1, a s-value of 2.35 ± 1.22 V decade-1, and an on/off current ratio of ∼4.1 × 106. The improvement of device characteristics was attributed to the reduction of back-channel defect by the formation of a thin CuSO4 back-channel passivation layer by the chemical reaction of interstitial Cu with S and O ions. An oxide-based complementary inverter using a p-channel Cu2O-TFT and a n-channel a-In-Ga-Zn-O-TFT was demonstrated with a high voltage gain of ∼230 at VDD = 70 V.

Frequency- and Power-Dependent Photoresponse of a Perovskite Photodetector Down to the Single-Photon Level.

Organometallic halide perovskites attract strong interests for their high photoresponsivity and solar cell efficiency. However, there was no systematic study of their power- and frequency-dependent photoresponsivity. We identified two different power-dependent photoresponse types in methylammonium lead iodide perovskite (MAPbI3) photodetectors. In the first type, the photoresponse remains constant from 5 Hz to 800 MHz. In the second type, absorption of a single photon can generate a persistent photoconductivity of 30 pA under an applied electric field of 2.5 × 104 V/cm. Additional absorbed photons, up to 8, linearly increase the persistent photoconductivity, which saturates with the absorption of more than 10 photons. This is different than single-photon avalanche detectors (SPADs) because the single-photon response is persistent as long as the device is under bias, providing unique opportunities for novel electronic and photonic devices such as analogue memories for neuromorphic computing. We propose an avalanche-like process for iodine ions and estimate that absorption of a single 0.38 aJ photon triggers the motion of 108-9 ions, resulting in accumulations of ions and charged vacancies at the MAPbI3/electrode interfaces to cause the band bending and change of electric material properties. We have made the first observation that single-digit photon absorption can alter the macroscopic electric and optoelectronic properties of a perovskite thin film.

Factors for inhibition of early discharge from the psychiatric emergency ward for elderly patients.

BACKGROUND: As society is aging, the number of elderly patients with psychiatric disorder, such as dementia, is increasing. The hospitalization period of elderly patients in psychiatric wards tends to be prolonged. In this study, we have determined the factors that inhibit early discharge from the psychiatric emergency ward for elderly patients in Japan. METHODS: The information was collected from patients admitted to our hospital's emergency ward for elderly patients with psychiatric disorders between May 2015 and April 2016. We compared various factors between the early discharge group and the non-early discharge group. In addition, we used a multiple logistic regression model to clarify the risk factors for non-early discharge. RESULTS: Of the 208 elderly patients, body mass index (BMI) and serum albumin level were significantly lower in the non-early discharge group. In addition, we also showed that higher serum C-reactive protein (CRP) (> 0.5 mg/dL) and use of seclusion or physical restraint significantly inhibited the early discharge of patients. The results of multiple logistic analysis showed that the BMI ≤ 17.5 kg/m2 (OR, 2.41 [95% confidence interval (CI) 1.06-5.46]), serum albumin level ≤ 30 g/L (OR, 3.78 [95% CI 1.28-11.16]), and use of seclusion or physical restraint (OR 3.78 [95% CI 1.53-9.37]) are particularly important explanatory factors. CONCLUSIONS: Hypoalbuminemia, low BMI, and the use of seclusion or physical restraint were identified as the factors that inhibit early discharge from the psychiatric emergency ward for elderly patients. These factors reflect malnutrition and extremely serious psychiatric symptoms.

Is high job control a risk factor for poor quality of life in workers with high autism spectrum tendencies? A cross-sectional survey at a factory in Japan.

OBJECTIVES: To examine the effect of autism spectrum (AS) tendencies and psychosocial job characteristics on health-related quality of life (HRQOL) among factory workers. METHODS: A questionnaire survey was administered to 376 Japanese factory employees from the same company (response rate: 83.6%) in 2010. Psychosocial job characteristics, including job demand, job control, and social support, were evaluated using the Job Content Questionnaire (JCQ). AS tendencies was assessed using the Autism-Spectrum Quotient (AQ), and HRQOL was assessed using the Medical Outcomes Study Short-Form General Health Survey (SF-8). Associations were investigated using multiple logistic regression analysis adjusted for confounders. RESULTS: In the multivariate analysis, AQ was positively (odds ratio [OR]: 3.94; 95% confidence interval [CI]: 1.70-9.73) and social support in the workplace was inversely (OR: 0.25; 95% CI: 0.10-0.57) associated with poor mental HRQOL. No significant interaction was observed between AQ and JCQ subitems. Only social support was inversely associated with poor physical HRQOL (OR and 95% CI for medium social support: 0.45 and 0.21-0.94), and a significant interaction between AQ and job control was observed (p=0.02), suggesting that high job control was associated with poor physical HRQOL among workers with high AQ, whereas low job control tended to be associated with poor physical HRQOL among others. CONCLUSIONS: Our results suggest that AS tendencies have a negative effect on workers' HRQOL and social support is a primary factor in maintaining HRQOL. Moreover, a structured work environment can maintain physical HRQOL in workers with high AS tendencies since higher job control will be stressful.

Psychometric properties of the parent and teacher forms of the Japanese version of the Strengths and Difficulties Questionnaire.

OBJECTIVE: This study examined the psychometric properties of the parent and teacher forms of the Japanese version of the Strengths and Difficulties Questionnaire (SDQ). METHOD: Parents and teachers of 1487 elementary school children (759 boys and 728 girls aged 6-12 years) participated in this study. RESULTS: The results of confirmatory factor analyses of the parent and teacher versions of the SDQ supported the five-factor structure reported in previous studies. However, factor invariance across sex was not observed. The alpha coefficients for the subscales of the SDQs varied between 0.55 and 0.86, the same reliability measures that were also reported in previous studies. Moreover, analyses of variance showed significant differences on all of the subscales according to sex and teacher-parent ratings. CONCLUSION: The factor structure of the SDQ was generally supported, but more gender-segregated investigations of the factor structures are needed. Parents tended to give higher ratings on the difficulties and strengths of children compared to the teachers. Boys were rated higher than girls were on difficulties, while girls were rated higher than boys were on strengths.

A clinical study of attention-deficit/hyperactivity disorder in preschool children--prevalence and differential diagnoses.

OBJECTIVE: We aimed to examine (1) the prevalence and characteristics of ADHD in preschool children, and (2) differential diagnoses among children who display symptoms of inattention and hyperactivity-impulsivity in early childhood. METHODS: The participants were children living in Kanie-cho, in Japan's Aichi Prefecture, who underwent their age 5 exams at the municipal health center between April 2009 and March 2011. We first extracted children who were observed to be inattentive or hyperactive-impulsive during their age 5 exams and considered as possibly having ADHD. We conducted follow-ups with these children using post-examination consultations, visits to preschools, and group rehabilitation. The results of the age 5 exams were combined with behavior observations and interview content obtained during subsequent follow-ups. A child psychiatrist and several clinical psychologists discussed these cases and made a diagnosis in accordance with the DSM-IV-TR. RESULTS: 91 (15.6%) of the 583 children selected were considered as possibly having ADHD; we were able to conduct follow-ups with 83 of the 91 children. Follow-up results showed that 34 children (5.8% of all participants) remained eligible for a diagnosis of ADHD. Diagnoses for the remaining children included: pervasive developmental disorders (six children, or 6.6% of suspected ADHD children), intellectual comprehension problems (four children, or 4.4%), anxiety disorders (seven children, or 7.7%), problems related to abuse or neglect (four children, or 4.4%), a suspended diagnosis for one child (1.1%), and unclear diagnoses for 29 children (31.9%). CONCLUSIONS: ADHD tendencies in preschool children vary with changing situations and development, and the present study provides prevalence estimates that should prove useful in establishing a diagnostic baseline.

[The neurotic disorders].

The clinical practice of child and adolescent psychiatry includes encounters with disorders not particular to childhood and adolescence, but seen in adulthood as well. For example, among the neurotic disorders, obsessive-compulsive disorder can be seen from around 3 years of age, with rapid rise in prevalence from around age 10. Increase is also seen in cases of anorexia nervosa from around age 11. This report examines the association between disorders in childhood and adolescence, in comparison to that in adulthood, with focus on obsessive-compulsive disorder. To start with, the characteristics of childhood onset cases with onset under age 7 were reviewed, revealing a relatively large proportion of subjects with experience of separation anxiety. Analyses revealed the possibility of anticipating obsessional tendencies in the parents of such subjects. Further clarification of the features of such early onset cases is hoped for in future. Next, we conducted a literature review comparing the characteristics of child and adolescent obsessive-compulsive disorder with that in adulthood. It has been determined that obsessive-compulsive symptoms in childhood and adolescence have a relatively unyielding 4-factor construct that persists through life, namely: 1) symmetry factor, 2) forbidden thoughts factor, 3) cleaning factor, and 4) hoarding factor. Of these, children with primary symptoms of hoarding are said to have poorer long-term diagnoses than children with other symptoms. Another point of note is the presence of large disparity regarding the prognosis of cases with concomitant tics. While the prognosis of childhood-obsessive compulsive disorder is generally favorable in many reports, the need for caution has also been noted regarding the possibility of transition on to schizophrenia in more than just a few cases.

Prefrontal overactivation, autonomic arousal, and task performance under evaluative pressure: a near-infrared spectroscopy (NIRS) study.

To study the mechanism underlying the influence of psychological pressure on task performance, we investigated the relationship between prefrontal activation, autonomic arousal, and performance in an n-back working memory task with 3 load levels (l-, 2-, and 3-back tasks) under evaluative pressure. The tasks were performed by 32 university students with or without evaluative observation by experimenters. The error rate and prefrontal activation were found to increase with pressure only in the highest load task (3-back). In contrast, autonomic arousal increased with pressure regardless of the task condition. Correlation analysis showed a positive correlation of the error rate with prefrontal activation in the 3-back task and no consistent correlation with autonomic arousal. We concluded that the inhibitory effect of evaluative pressure on task performance is mediated by prefrontal overactivation rather than autonomic arousal.

Hemodynamic changes in the prefrontal cortex during digit span task: a near-infrared spectroscopy study.

BACKGROUND/AIMS: In this study, we examined changes in the concentrations of oxygenated and deoxygenated hemoglobin (oxy- and deoxy-Hb, respectively) in the prefrontal cortex (PFC) during the digit span task by using near-infrared spectroscopy (NIRS). METHODS: The digit span task consists of the digit span forward and backward tasks. The tasks were performed by 22 healthy undergraduate students who participated in this study. Differences in the mean concentrations of oxy-Hb and deoxy-Hb between the baseline and task intervals were evaluated. RESULTS: In digit span backward, oxy-Hb was significantly higher during the task interval than during the baseline. Further, deoxy-Hb was significantly lower during the task interval than during the baseline in both digit span forward and digit span backward. Digit span forward performance was significantly higher for the right-PFC-dominant group than for the left-PFC-dominant group. CONCLUSION: These results suggest that the digit span backward task is more demanding and requires greater activation of the prefrontal cortex than the digit span forward task. Our NIRS findings suggest that the digit span backward task involves executive functioning.