Ballistic two-dimensional InSe transistors.

The International Roadmap for Devices and Systems (IRDS) forecasts that, for silicon-based metal-oxide-semiconductor (MOS) field-effect transistors (FETs), the scaling of the gate length will stop at 12 nm and the ultimate supply voltage will not decrease to less than 0.6 V (ref. 1). This defines the final integration density and power consumption at the end of the scaling process for silicon-based chips. In recent years, two-dimensional (2D) layered semiconductors with atom-scale thicknesses have been explored as potential channel materials to support further miniaturization and integrated electronics. However, so far, no 2D semiconductor-based FETs have exhibited performances that can surpass state-of-the-art silicon FETs. Here we report a FET with 2D indium selenide (InSe) with high thermal velocity as channel material that operates at 0.5 V and achieves record high transconductance of 6 mS µm-1 and a room-temperature ballistic ratio in the saturation region of 83%, surpassing those of any reported silicon FETs. An yttrium-doping-induced phase-transition method is developed for making ohmic contacts with InSe and the InSe FET is scaled down to 10 nm in channel length. Our InSe FETs can effectively suppress short-channel effects with a low subthreshold swing (SS) of 75 mV per decade and drain-induced barrier lowering (DIBL) of 22 mV V-1. Furthermore, low contact resistance of 62 Ω µm is reliably extracted in 10-nm ballistic InSe FETs, leading to a smaller intrinsic delay and much lower energy-delay product (EDP) than the predicted silicon limit.

Unzipping Carbon Nanotubes to Sub-5-nm Graphene Nanoribbons on Cu(111) by Surface Catalysis.

Graphene nanoribbons (GNRs) are promising in nanoelectronics for their quasi-1D structures with tunable bandgaps. The methods for controllable fabrication of high-quality GNRs are still limited. Here a way to generate sub-5-nm GNRs by annealing single-walled carbon nanotubes (SWCNTs) on Cu(111) is demonstrated. The structural evolution process is characterized by low-temperature scanning tunneling microscopy. Substrate-dependent measurements on Au(111) and Ru(0001) reveal that the intermediate strong SWCNT-surface interaction plays a pivotal role in the formation of GNRs.

An Ultrathin Flexible Programmable Spin Logic Device Based on Spin-Orbit Torque.

Flexible electronic devices have shown increasingly promising value facilitating our daily lives. However, flexible spintronic devices remain in their infancy. Here, this research demonstrates a type of nonvolatile, low power dissipation, and programmable flexible spin logic device, which is based on the spin-orbit torque in polyimide (PI)/Ta/Pt/Co/Pt heterostructures fabricated via capillary-assisted electrochemical delamination. The magnetization switching ratio is shown to be about 50% for the flexible device and does not change after 100 cycles of bending, indicating the device has stable performance. By designing the path of pulse current, five Boolean logic gates AND, NAND, NOT, NOR, and OR can be realized in an integrated two-element device. Moreover, such peeling-off devices can be successfully transferred to almost any substrate, such as paper and human skin, and maintain high performance. The flexible PI/Ta/Pt/Co/Pt spin logic device serves as logic-in-memory architecture and can be used in wearable electronics.

Ultra-Strong Comprehensive Radiation Effect Tolerance in Carbon Nanotube Electronics.

Carbon nanotube (CNT) field-effect transistors (FETs) have been considered ideal building blocks for radiation-hard integrated circuits (ICs), the demand for which is exponentially growing, especially in outer space exploration and the nuclear industry. Many studies on the radiation tolerance of CNT-based electronics have focused on the total ionizing dose (TID) effect, while few works have considered the single event effects (SEEs) and displacement damage (DD) effect, which are more difficult to measure but may be more important in practical applications. Measurements of the SEEs and DD effect of CNT FETs and ICs are first executed and then presented a comprehensive radiation effect analysis of CNT electronics. The CNT ICs without special irradiation reinforcement technology exhibit a comprehensive radiation tolerance, including a 1 × 104 MeVcm2 mg-1 level of the laser-equivalent threshold linear energy transfer (LET) for SEEs, 2.8 × 1013 MeV g-1 for DD and 2 Mrad (Si) for TID, which are at least four times higher than those in conventional radiation-hardened ICs. The ultrahigh intrinsic comprehensive radiation tolerance will promote the applications of CNT ICs in high-energy solar and cosmic radiation environments.

Amplification-Free Detection of SARS-CoV-2 Down to Single Virus Level by Portable Carbon Nanotube Biosensors.

The rapid and sensitive detection of trace-level viruses in a simple and reliable way is of great importance for epidemic prevention and control. Here, a multi-functionalized floating gate carbon nanotube field effect transistor (FG-CNT FET) based biosensor is reported for the single virus level detection of SARS-CoV-2 virus antigen and RNA rapidly with a portable sensing platform. The aptamers functionalized sensors can detect SARS-CoV-2 antigens from unprocessed nasopharyngeal swab samples within 1 min. Meanwhile, enhanced by a multi-probe strategy, the FG-CNT FET-based biosensor can detect the long chain RNA directly without amplification down to single virus level within 1 min. The device, constructed with packaged sensor chips and a portable sensing terminal, can distinguish 10 COVID-19 patients from 10 healthy individuals in clinical tests both by the RNAs and antigens by a combination detection strategy with an combined overall percent agreement (OPA) close to 100%. The results provide a general and simple method to enhance the sensitivity of FET-based biochemical sensors for the detection of nucleic acid molecules and demonstrate that the CNT FG FET biosensor is a versatile and reliable integrated platform for ultrasensitive multibiomarker detection without amplification and has great potential for point-of-care (POC) clinical tests.

[Penile cancer with perineural invasion is more prone to postoperative recurrence].

OBJECTIVE: To explore the correlation between perineural invasion and postoperative recurrence in patients surgically treated for penile cancer. METHODS: We conducted a retrospective analysis of the clinical data on 18 penile cancer patients surgically treated in our hospital from January 2018 to December 2021, 8 with postoperative recurrence (the recurrence group) and the other 10 without (the non-recurrence control group). We compared the two groups of patients in the age of onset, tumor-node-metastasis (TNM) stages, American Joint Committee on Cancer (AJCC) prognosis stages, surgical methods, perineural invasion and recurrence time. We analyzed the differences in postoperative recurrence using the Kaplan Meier plotted survival curve and in independent risk factors in predicting postoperative recurrence using the ROC curve. RESULTS: Compared with the non-recurrence controls, the patients in the recurrence group had a significantly older age of onset (P=0.0411) and severer perineural invasion (P<0.001), and those with perineural invasion had a shorter recurrence time (P<0.001), which was an independent risk factor for postoperative recurrence. The areas under the ROC curves for perineural invasion and age were 0.885 and 0.213, respectively. CONCLUSION: Penile cancer with perineural invasion is more prone to and perineural invasion is an independent risk factor for postoperative recurrence of the malignancy.

The dose-response relationship of serum uric acid with Dyslipidaemia and its components: a cross-sectional study of a Chinese multi-ethnic cohort.

BACKGROUND: The association between serum uric acid (SUA) and the components of dyslipidaemia and their dose-response relationships have not been thoroughly explored. This study assessed the relationship between SUA and each dyslipidaemia component in Dong, Miao, and Bouyei populations in Guizhou by sex and ethnicities and investigated the dose-response relationship. METHODS: In total, 16,092 participants aged 30-79 years from The China Multi-Ethnic Cohort (CMEC) Study were examined. Multivariable logistic regression models were applied to explore the relationship between SUA and each dyslipidaemia component by sex and three ethnicities. The dose-response associations between SUA and various dyslipidaemias were investigated using restricted cubic spline regression. RESULTS: After controlling for confounding factors, the SUA level in total participants positively correlated with each dyslipidaemia component, and women had higher odds ratios (ORs) for each dyslipidaemia component than men (P for trend < 0.001). At the SUA level > 6.37 mg/dL, ORs (95% CI) for dyslipidaemia in the Dong, Miao and Bouyei were 2.89 (2.00-4.19), 2.43 (1.70-3.48), and 3.26 (2.23-4.78), respectively. When the SUA concentration increased by 1 mg/dL, the ORs (95% CI) for total dyslipidaemia was 1.31 (1.24-1.37). A positive dose-response but nonlinear association was found between SUA and total dyslipidaemia, high total cholesterol, and low HDL, whereas an inverse U-shaped association was found between SUA and high LDL-C ( P-nonlinear< 0.0001). CONCLUSION: The SUA level was positively correlated with each dyslipidaemia component in Dong, Miao, and Bouyei adults, and sex and ethnic differences were also found. A nonlinear dose-response relationship was found between SUA levels and dyslipidaemia and its components. Further research is warranted to investigate the causal link between SUA levels and dyslipidaemia incidence.

[Association of phthalate and polycyclic aromatic hydrocarbon exposure during early pregnancy with premature delivery: A cohort study].

OBJECTIVE: To explore the relationship of the exposure to phthalate esters (PAE) and polycyclic aromatic hydrocarbons (PAH) with clinical premature delivery during early pregnancy. METHODS: We conducted a baseline questionnaire survey among 821 pregnant women undergoing prenatal examination in Hubei Provincial Maternal and Child Health Care Hospital, collected their morning urine samples and followed them up to the outcomes of pregnancy. We quantitatively analyzed 10 PAE and 10 PAH metabolites in the urine samples, followed by Mann-Whitney U test, chi-square test, and logistic regression analysis. RESULTS: The detection rate of the 5 factors exposed to was >80% while that of phthalic acid monobenzyl ester (MBzP) was <50% in PAEs; that of the 5 factors exposed to was >80%, that of 3-hydroxyphene (3-OHPHE) was 86.91% while that of 4-hydroxyphene (4-OHPHE) was <50% in PAHs. Logistic regression analysis showed that the risk of premature delivery was higher in the high MBzP- than in the low MBzP-exposure group (aOR = 2.26, 95% CI: 1.17－4.39). CONCLUSION: High MBzP-exposure may be a risk factor for premature delivery.

Host-Guest Molecular Interaction Enabled Separation of Large-Diameter Semiconducting Single-Walled Carbon Nanotubes.

Semiconducting single-walled carbon nanotubes (s-SWCNTs) with a diameter of around 1.0-1.5 nm, which present bandgaps comparable to silicon, are highly desired for electronic applications. Therefore, the preparation of s-SWCNTs of such diameters has been attracting great attention. The inner surface of SWCNTs has a suitable curvature and large contacting area, which is attractive in host-guest chemistry triggered by electron transfer. Here we reported a strategy of host-guest molecular interaction between SWCNTs and inner clusters with designed size, thus selectively separating s-SWCNTs of expected diameters. When polyoxometalate clusters of ∼1 nm in size were filled in the inner cavities of SWCNTs, s-SWCNTs with diameters concentrated at ∼1.3-1.4 nm were selectively extracted with the purity of ∼98% by a commercially available polyfluorene derivative. The field-effect transistors built from the sorted s-SWCNTs showed a typical behavior of semiconductors. The sorting mechanisms associated with size-dependent electron transfer from nanotubes to inner polyoxometalate were revealed by the spectroscopic and in situ electron microscopic evidence as well as the theoretical calculation. The polyoxometalates with designable size and redox property enable the flexible regulation of interaction between the nanotubes and the clusters, thus tuning the diameter of sorted s-SWCNTs. The present sorting strategy is simple and should be generally feasible in other SWCNT sorting techniques, bringing both great easiness in dispersant design and improved selectivity.

Low Residual Carrier Concentration and High Mobility in 2D Semiconducting Bi2O2Se.

The air-stable and high-mobility two-dimensional (2D) Bi2O2Se semiconductor has emerged as a promising alternative that is complementary to graphene, MoS2, and black phosphorus for next-generation digital applications. However, the room-temperature residual charge carrier concentration of 2D Bi2O2Se nanoplates synthesized so far is as high as about 1019-1020 cm-3, which results in a poor electrostatic gate control and unsuitable threshold voltage, detrimental to the fabrication of high-performance low-power devices. Here, we first present a facile approach for synthesizing 2D Bi2O2Se single crystals with ultralow carrier concentration of ∼1016 cm-3 and high Hall mobility up to 410 cm2 V-1 s-1 simultaneously at room temperature. With optimized conditions, these high-mobility and low-carrier-concentration 2D Bi2O2Se nanoplates with domain sizes greater than 250 µm and thicknesses down to 4 layers (∼2.5 nm) were readily grown by using Se and Bi2O3 powders as coevaporation sources in a dual heating zone chemical vapor deposition (CVD) system. High-quality 2D Bi2O2Se crystals were fabricated into high-performance and low-power transistors, showing excellent current modulation of >106, robust current saturation, and low threshold voltage of -0.4 V. All these features suggest 2D Bi2O2Se as an alternative option for high-performance low-power digital applications.

[Comparison of the disposable circumcision stapler, disposable prepuce ligator and traditional surgical method in circumcision].

OBJECTIVE: To compare the effects and complications of the disposable circumcision stapler, disposable prepuce ligator and traditional surgical method in circumcision. METHODS: This retrospective study included 327 cases of phimosis or redundant prepuce treated by circumcision with the disposable circumcision stapler (the DCS group, n = 133), disposable prepuce ligator (the DPL group, n = 105) or traditional surgical method (the TS group, n = 89) in our hospital from June 2019 to June 2020. We compared the three surgical methods in terms of operation time, intraoperative blood loss, pain score, satisfaction of the patients with the penile appearance and incidence rates of incision edema, hematoma, infection and dehiscence. RESULTS: The DCS and DPL groups, compared with the TS group, showed significantly shorter operation time (ï¼»9.72 ± 2.17ï¼½ and ï¼»10.57 ± 2.31ï¼½ vs ï¼»36.13 ± 6.85ï¼½ min, P < 0.01), less intraoperative blood loss (ï¼»2.07 ± 0.96ï¼½ and ï¼»2.53 ± 1.46ï¼½ vs ï¼»14.33 ± 4.92ï¼½ ml, P < 0.01) and higher appearance satisfaction score (4.07 ± 0.80 and 3.93 ± 0.96 vs 3.13 ± 1.06, P < 0.05). The DCS and TS groups, in comparison with the DPL group, exhibited markedly lower pain score (1.87 ± 0.99 and 2.27 ± 1.16 vs 3.87 ± 1.30, P < 0.01) and the rates of postoperative incision hematoma (3.01% and 2.25% vs 9.52%, P < 0.05), and infection and dehiscence (2.45% and 2.04% vs 8.07%, P < 0.05). The postoperative rate of incision edema was remarkably lower in the DCS than in the DPL and CS groups (10.2% vs 20.2% and 23.5%, P < 0.05). CONCLUSIONS: Circumcision with the disposable circumcision stapler, with the advantages of simple operation, short operation time, less bleeding, less pain, satisfactory appearance, and lower incidence of complications, deserves clinical application and promotion.

[Primary urothelial carcinoma of the prostate: A case report and review of the literature].

OBJECTIVE: To investigate the clinical diagnosis, treatment and prognosis of primary urothelial carcinoma of the prostate. METHODS: We retrospectively analyzed the clinical data on one case of primary urothelial carcinoma of the prostate and reviewed the relevant published literature. RESULTS: The patient, aged 83 years old and diagnosed with primary urothelial carcinoma of the prostate, was treated by neoadjuvant chemotherapy with gemcitabine plus cisplatin preoperatively, injected with 5-fluorouracil into the cutting edge of the tumor intraoperatively, and pathologically confirmed with high-grade invasive primary urothelial carcinoma of the prostate, followed by adjuvant chemotherapy with gemcitabine plus cisplatin. No recurrence or metastasis was observed during 1-year follow-up. CONCLUSIONS: Primary urothelial carcinoma of the prostate is rare and highly malignant. If the tumor is localized, the patient needs to be treated by neoadjuvant chemotherapy preoperatively, injection with anti-tumor drugs into the cutting edge of the tumor intraoperatively, and adjuvant chemotherapy and regular follow-up postoperatively.

Platycosides P and Q, two new triterpene saponins from Platycodon grandiflorum.

The EtOH extract of the roots of Platycodon grandiflorum afforded two new triterpene saponins platycoside P (1) and platycoside Q (2). Their structures were elucidated based on spectroscopic means and hydrolysis products. These compounds were evaluated for inhibitory activity against LPS-induced TNF-α production in RAW 246.7 macrophages. Compounds 1 and 2 showed inhibitory activity with the inhibition ratios (%) of 38.6 and 44.1 at 50 µM, respectively.

Konjac glucomannan octenyl succinate (KGOS) as an emulsifier for lipophilic bioactive nutrient encapsulation.

BACKGROUND: Konjac glucomannan octenyl succinate (KGOS) has excellent emulsification properties and can potentially be used in the food industry as an emulsifier, stabilizer and microcapsule wall material. In the present study, the in vitro digestion properties and emulsification capability and stability of KGOS were studied to evaluate the transport and encapsulation characteristics of KGOS with insoluble bioactive nutrients. RESULTS: Confocal scanning laser microscopy (CSLM) suggested that oil droplets could be encapsulated by KGOS into regular spheres. In vitro digestion properties showed that KGOS is effective for colon-targeted transport. ß-Carotene was selected as a representative lipophilic bioactive compound to evaluate the emulsification characteristics of KGOS. The loading capacity of the 0.4 mg mL-1 KGOS solution for ß-carotene was 3.26%, and transmission electron microscopy suggested that the self-aggregate particles of KGOS/ß-carotene (KGOSC) were more uniform than KGOS. With a composition of 0.03% ß-carotene, 0.3% KGOS and 10% medium-chain triglycerides, the emulsification yield of the KGOSC nanoemulsion was more than 95%. After 30 days of storage, the particle size and polydispersity index of the KGOSC nanoemulsion were less than 5 nm and 0.5, respectively, and the sensitivity of KGOSC nanoemulsions to storage conditions decreased in the order temperature, oxygen and light. CONCLUSION: The results of this study suggested that KGOS is a good potential emulsifier and stabilizer for lipophilic bioactive nutrient encapsulation. © 2018 Society of Chemical Industry.

Carbon nanotube radio-frequency electronics.

Carbon nanotube (CNT) is considered a promising material for radio-frequency (RF) applications, owing to its high carrier mobility and saturated drift velocity, as well as ultra-small intrinsic gate capacitance. Here, we review progress on CNT-based devices and integrated circuits for RF applications, including theoretical projection of RF performance of CNT-based devices, preparation of CNT materials, fabrication, optimization of RF field-effect transistors (FETs) structures, and ambipolar FET-based RF applications, and we outline challenges and prospects of CNT-based RF applications.

Highly Uniform Carbon Nanotube Field-Effect Transistors and Medium Scale Integrated Circuits.

Top-gated p-type field-effect transistors (FETs) have been fabricated in batch based on carbon nanotube (CNT) network thin films prepared from CNT solution and present high yield and highly uniform performance with small threshold voltage distribution with standard deviation of 34 mV. According to the property of FETs, various logical and arithmetical gates, shifters, and d-latch circuits were designed and demonstrated with rail-to-rail output. In particular, a 4-bit adder consisting of 140 p-type CNT FETs was demonstrated with higher packing density and lower supply voltage than other published integrated circuits based on CNT films, which indicates that CNT based integrated circuits can reach to medium scale. In addition, a 2-bit multiplier has been realized for the first time. Benefitted from the high uniformity and suitable threshold voltage of CNT FETs, all of the fabricated circuits based on CNT FETs can be driven by a single voltage as small as 2 V.

[Research on Chemical Constituents of Bamboo Fiber Cell Wall Based on Nano-IR Technology].

Nano-IR technology was firstly employed on bamboo fiber research with purpose to further understand the fine structure of bamboo fiber cell wall. Chemical constituent distribution of bamboo fiber was studied, and the feasibility of the novel technology was discussed by comparing with other traditional methods. The results showed that Nano-IR technology, which has made a breakthrough on diffraction limit of traditional infrared spectroscopy, can acquire nano-scale infrared spectrum of bamboo cell wall in situ condition. The characteristic peak positions of Nano-IR spectrum is basically the same with that of microscopic FTIR spectrum, indicating that Nano-IR spectrum can reveal the chemical information of bamboo cell wall. The results of the present work suggested that nano-IR technology could be an effective research tool in research of nano chemical composition distribution of bamboo cell wall.

[Study on the Crystal Structure of Cellulose in Bamboo with Synchrotron Radiation Wide Angle X-Ray Scattering].

The crystal structure of cellulose will directly affect the properties of bamboo fiber -reinforced composite, but the unit cell of native cellulose in bamboo has never been investigated. The most accepted model for the structure of native cellulose is Meyer-Misch model which provides a reference to understand the unit cell of native cellulose in bamboo. The native cellulose consists of two different crystal structures (Ⅰ(α) and Ⅰ(ß)) which exist in different plants with different proportions. Because of this situation, the crystal structure of bamboo cellulose should have a unique model. The moso bamboo (Phyllostachys edulis (Carr. ) H. de Lehaie)was selected. The crystal structure of cellulose of bamboo was investigated with two dimensional synchrotron radiation wide angle X-ray scattering (SR-WAXS). The values of the interplanar spacings of each peak were obtained from SR-WAXS patterns, and then crystal structure parameters were calculated according to monoclinic crystal system. The results show that the fibre axis of a bamboo cellulose unit cell with a monoclinic unit cell of a=8.35 Å, b (fiber axis)=10.38 Å, c=8.02 Å, ß=84.99°. This model has a two antiparallel arrangement for the chains in unit cell, with four glucose residues. Thus, the model may be used to provide a theoretical basis for high value-added bamboo fiber -reinforced composite.

Length scaling of carbon nanotube electric and photo diodes down to sub-50 nm.

Carbon nanotubes (CNTs) are promising candidates for future optoelectronics and logic circuits.1-3 Sub-10 nm channel length CNT transistors have been demonstrated with superb performance.4 Yet, the scaling of CNT p-n diodes or photodiodes, basic elements for most optoelectronic devices, is held back on a scale of micrometers.5-8 Here, we demonstrate that CNT diodes fabricated via a dopant-free technique show good rectifying characteristics and photovoltaic response even when the channel length is scaled to sub-50 nm. By making a trade-off between performance and size, a diode with both channel length and contact width around 100 nm, fabricated on a CNT with a small diameter (d ∼ 1.2 nm), shows a photovoltage of 0.24 V and a fill factor of up to 60%. Study on the dependence of turn-on voltage on scaled channel length reveals transferred charges induced potential barrier at the contact in long channel diodes and the effect of self-adjusting charge distribution. This effect could be utilized for realizing stable and high performance sub-100 nm pitch CNT diodes. As elementary building blocks, such tiny electric and photodiodes could be used in nanoscale rectifiers, photodetectors, light sources, and high-efficiency photovoltaic devices.

Modularized construction of general integrated circuits on individual carbon nanotubes.

While constructing general integrated circuits (ICs) with field-effect transistors (FETs) built on individual CNTs is among few viable ways to build ICs with small dimension and high performance that can be compared with that of state-of-the-art Si based ICs, this has not been demonstrated owing to the absence of valid and well-tolerant fabrication method. Here we demonstrate a modularized method for constructing general ICs on individual CNTs with different electric properties. A pass-transistor-logic style 8-transistor (8-T) unit is built, demonstrated as a multifunctional function generator with good tolerance to inhomogeneity in the CNTs used and used as a building block for constructing general ICs. As an example, an 8-bits BUS system that is widely used to transfer data between different systems in a computer is constructed. This is the most complicated IC fabricated on individual CNTs to date, containing 46 FETs built on six individual semiconducting CNTs. The 8-T unit provides a good basis for constructing complex ICs to explore the potential and limits of CNT ICs given the current imperfection in available CNT materials and may also be developed into a universal and efficient way for constructing general ICs on ideal CNT materials in the future.