Improvement of Shen'ge formula on heart function in diastolic heart failure: A protocol for randomized, double-blind, placebo-controlled clinical study

INTRODUCTION

Diastolic heart failure (DHF) is an important pathological type of heart failure, that involves multiple organ dysfunction and multiple complications. The prevalence of DHF is high, and effective treatments are lacking. Chinese herbs are an alternative therapy for DHF. Shen'ge formula (SGF) is a classical formula from which patients can benefit, but convincing evidence of its efficacy is lacking. Therefore, we designed this randomized controlled trial protocol.

METHODS/DESIGN

This randomized, double-blind, placebo-controlled clinical trial will evaluate the efficacy and safety of SGF in the treatment of DHF. A total of 130 patients with DHF will be enrolled in the trial and treated with SGF granules or placebo for 12 weeks and followed up for 12 weeks. The primary outcome measurement will be to changes in plasma N-terminal brain natriuretic peptide precursor before versus after treatment, while the second primary outcome measurement will be changes in heart function before versus after treatment and the 12-week follow-up period. It will also include echocardiography, a cardiopulmonary exercise test, cardiac function grading, traditional Chinese medicine syndrome score, and the Minnesota Heart Failure Quality of Life Scale. Adverse events will be evaluated throughout the trial.

DISCUSSION

The results of this trial will demonstrate whether SGF could alleviate symptoms, improve cardiac function, reduce readmission rates, and improve quality of life of patients with DHF.

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR2000036533, registered on August 24, 2020.

An improved method used for evaluating potential environmental pollution risk based on spatial distribution and density of farms

The livestock manure nitrogen load on farmland (LMNLF) is often used to assess the potential environmental pollution risk of livestock manure nitrogen nutrient (LMN) in a target region. First, the LMNLF of Wuhan city is calculated, and the potential environmental pollution risk of LMN is mainly concentrated in Jiangxia District, Xinzhou District, and Huangpi District, but does not exceed the European Union (EU) standards. Heat map results also certificate this conclusion. Therefore, these three districts are the research emphases. Second, considering spatial distribution of farms, an improved LMNLF method is proposed combining the previous LMNLF and density-based spatial clustering of applications with noise (DBSCAN) methods. Several regions with pollution risks including seven regions in Jiangxia District, one in Xinzhou District, and one in Huangpi District are found out using the improved LMNLF method. Third, to evaluate the carrying capacity of the intensive breeding areas more reasonably, 2 km is taken as the farthest transportation distance of manure; there is still one region in Huangpi District which has serious pollution risk on the environment. These above results can help evaluate the pollution degree of livestock manure to the surrounding environment more precisely.

Millisecond Conversion of Metastable 2D Materials by Flash Joule Heating

Controllable phase engineering is vital for precisely tailoring material properties since different phase structures have various electronic states and atomic arrangements. Rapid synthesis of thermodynamically metastable materials, especially two-dimensional metastable materials, with high efficiency and low cost remains a large challenge. Here we report flash Joule heating (FJH) as an electrothermal method to achieve the bulk conversion of transition metal dichalcogenides, MoS₂ and WS₂, from 2H phases to 1T phases in milliseconds. The conversions can reach up to 76% of flash MoS₂ using tungsten powder as conductive additive. Different degrees of phase conversion can be realized by controlling the FJH conditions, such as reaction duration and additives, which allows the study of ratio-dependent properties. First-principles calculations confirm that structural processes associated with the FJH, such as vacancy formation and charge accumulation, result in stabilization of the 1T phases. FJH offers rapid access to bulk quantities of the hitherto hard-to-access 1T phases, a promising method for further fundamental research and diverse applications of metastable phases.

A ratiometric fluorescent probe for the detection of β-galactosidase and its application

Herein, a coumarin fluorescent probe (Probe 1) was developed for the ratiometric detection of β-galactosidase (β-gal) activity. The detection range was 0–0.1 U mL⁻¹ and 0.2–0.8 U mL⁻¹, and the limit of detection (LOD) was 0.0054 U mL⁻¹. Moreover, the luminous intensity of Probe 1 increased gradually with increase in β-gal activity. It could be observed under 254 nm UV irradiation by the naked eye. Furthermore, this method only required a small amount of sample (20 μL) and a short analytical time (30 min) for the detection of β-gal activity with a low LOD. Probe 1 was successfully used to detect β-gal activity in real fruit samples, and can be applied to the quantitative and qualitative detection of β-gal activity.

A ratiometric fluorescent probe was successfully used as a tool to determine β-galactosidase activity in fruits.

Characterizing hydrogen bonds in crystalline form of guanidinium salicylate in the terahertz range

For pharmaceutical compounds with poor solubility, there is an effective method to address this dilemma without tampering their intrinsic chemical properties by forming weak hydrogen bonds. Guanidinium salicylate, which is a typical pharmaceutical salt with a complex crystal structure, was systematically investigated by terahertz time-domain spectroscopy combined with density functional theory in order to obtain the complete information of weak hydrogen bonds. As a result of the influence of weak hydrogen bonds, there are substantial differences between guanidinium salicylate and its parent molecule (salicylic acid) in the experimental fingerprint spectra in the range of 0.2-2.5 THz, such as the number, amplitude and frequency positions of absorption peaks. With the help of isolated molecule density functional theory calculations, the possible sites of weak hydrogen bonds were determined by natural bond orbital analysis. It can be concluded that there is an intricate hydrogen bond network due to the polar distribution of molecular electrostatic potential. Furthermore, all THz absorption peaks were assigned to their corresponding vibrational modes and the complete information of the related hydrogen bonds (including type, role, angle, and bond length) was determined by using dispersion-corrected density functional theory. The results laid a good foundation for further study on the enhancement of solubility of pharmaceutical salts by forming weak hydrogen bonds.

SPM control on the partitioning and balance of 210Po and 210Pb in high-turbidity surface waters of the East China Sea

²¹⁰Po and ²¹⁰Pb are well-known tracer pairs for some biomass and chemical processes in the marine system. In this study, ²¹⁰Po and ²¹⁰Pb were analyzed in surface seawater collected from the East China Sea (ECS), in atmospheric deposition, and in riverine input water collected along the ECS coast. The atmospheric fallouts of ²¹⁰Po and ²¹⁰Pb were higher in the dry season, due to the arrival of storm dust from the northwestern region of China. In the riverine input water, the particulate ²¹⁰Po and ²¹⁰Pb dominated (corresponding to 33-94% and 50-92% of the total, respectively), especially during the flood season. In the surface seawaters, the percentage of particulate ²¹⁰Po (17-85%) was generally greater than that of ²¹⁰Pb (10-76%). Additionally, in the Changjiang Estuary, log K_d(Po) and log K_d(Pb) were negatively correlated with log suspended particulate matter (SPM) (R = 0.71, P = 0.013 for Po, R = 0.67, P = 0.019 for Pb). ²¹⁰Pb showed a stronger "particle effect" than ²¹⁰Po when SPM <1.00 mg L^-1, and vice versa when SPM >1.00 mg L^-1. The deficit of ²¹⁰Po relative to ²¹⁰Pb gradually decreased from the Changjiang Diluted Water, to the Shelf Merged Water and the Taiwan Warm Current Water. The mass balance of ²¹⁰Po and ²¹⁰Pb in the water column of the estuary indicated that the Changjiang River was the dominating input source (providing 91% and 88% of the ²¹⁰Po and ²¹⁰Pb, respectively); meanwhile, the shelf export was the dominating output source (accounting for 68% and 78% of the ²¹⁰Po and ²¹⁰Pb, respectively).

Involvement of CsWRKY70 in salicylic acid-induced citrus fruit resistance against Penicillium digitatum

Penicillium digitatum causes serious losses in postharvest citrus fruit. Exogenous salicylic acid (SA) can induce fruit resistance against various pathogens, but the mechanism remains unclear. Herein, a transcriptome-based approach was used to investigate the underlying mechanism of SA-induced citrus fruit resistance against P. digitatum. We found that CsWRKY70 and genes related to methyl salicylate (MeSA) biosynthesis (salicylate carboxymethyltransferase, SAMT) were induced by exogenous SA. Moreover, significant MeSA accumulation was detected in the SA-treated citrus fruit. The potential involvement of CsWRKY70 in regulating CsSAMT expression in citrus fruit was studied. Subcellular localization, dual luciferase, and electrophoretic mobility shift assays and an analysis of transient expression in fruit peel revealed that the nucleus-localized transcriptional activator CsWRKY70 can activate the CsSAMT promoter by recognizing the W-box element. Taken together, the findings from this study offer new insights into the transcriptional regulatory mechanism of exogenous SA-induced disease resistance in Citrus sinensis fruit.

Growth of Ultraflat Graphene with Greatly Enhanced Mechanical Properties

Graphene grown on Cu by chemical vapor deposition is rough due to the surface roughening of Cu for releasing interfacial thermal stress and/or graphene bending energy. The roughness degrades the electrical conductance and mechanical strength of graphene. Here, by using vicinal Cu(111) and flat Cu(111) as model substrates, we investigated the critical role of original surface topography on the surface deformation of Cu covered by graphene. We demonstrated that terrace steps on vicinal Cu(111) dominate the formation of step bunches (SBs). Atomically flat graphene with roughness down to 0.2 nm was grown on flat Cu(111) films. When SB-induced ripples were avoided, as-grown ultraflat graphene maintained its flat feature after transfer. The ultraflat graphene exhibited extraordinary mechanical properties with Young's modulus ≈ 940 GPa and strength ≈ 117 GPa, comparable to mechanical exfoliated ones. Molecular dynamics simulation revealed the mechanism of softened elastic response and weakened strength of graphene with rippled structures.

Lee Silverman Voice Treatment for dysarthria in patients with Parkinson's disease: a systematic review and meta-analysis

Approximately 89% of patients with Parkinson's disease (PD) suffer from dysarthria. Lee Silverman Voice Treatment (LSVT), a behavioral therapy, aims to improve speech and voice functions. The objective was to assess the effectiveness of LSVT compared with other/no speech interventions for dysarthria in patients with PD. Electronic databases, including PubMed, Embase and the Cochrane Library, were searched. The publication date of all included studies was before 6 March 2020. Only randomized controlled trials (RCTs) that evaluated the LSVT intervention compared with other/no speech intervention were considered. The data obtained from the included studies were described and the mean differences were calculated. Eight RCTs were included in this meta-analysis comparing LSVT with other/no speech interventions. In the comparison of LSVT versus no intervention, vocal intensity for sustained 'Ah' phonation, reading the 'Rainbow passage', monologue and describing a picture increased by 8.87, 4.34, 3.25 and 3.31 dB, respectively, after 1 month of therapy. Compared with the respiratory therapy group, the LSVT group also showed significant improvement in vocal intensity for sustained 'Ah' phonation, reading the 'Rainbow passage' and monologue immediately after treatment (13.39, 6.66 and 3.19 dB). Positive improvement still existed after 24 months. There was no difference in the therapeutic effect between face-to-face and online LSVT. The effectiveness of LSVT for dysarthria in patients with PD was verified in these trials. However, future RCTs with sufficient participants are essential to evaluate the effectiveness of LSVT for dysarthria.

Effects on Suxiao Jiuxin Pills in the Treatment of Patients with Acute Coronary Syndrome Undergoing Early Percutaneous Coronary Intervention: A Multicenter Randomized Double-Blind Placebo-Controlled Trial

Objectives: Acute coronary syndrome (ACS) is an acute disease with high mortality. Although early percutaneous coronary intervention (PCI) is proved to be the practical approach in treating ACS, the incidence of cardiovascular events is still far from satisfactory. The combination of Suxiao Jiuxin Pill (SJP) and Western medicine is one conventional approach in the treatment of ACS. Many elementary and clinical trials have proved the efficacy and safety in the improvement of cardiocerebral vascular conditions. The aim of this project is to evaluate the safety and efficacy of SJP on ACS with early PCI patients. Trial Design: This is a multicenter randomized, double-blind placebo-controlled trial. Trial registration: ChiCTR-TRC-13003053. Settings: Hospitals. Subjects: A total of 200 ACS with early PCI patients were randomly divided into SJP group (n = 100) and placebo group (n = 100). Interventions: The SJP group was treated with routine treatment and SJP (taking eight SJP pills orally each time, three times per day). The placebo group was treated with routine treatment along with equal amounts of SJP placebo. The course of treatment was 6 months and a follow-up visit at 12 months. Outcome Measures: Assessments of major adverse cardiovascular events (MACE), safety assessments, adverse events, left ventricular systolic function (LVEF), Seattle angina questionnaire (SAQ), troponin C (cTNI), C-reactive protein (CRP), fibrinogen (Fib), and cystatin C (cysC). Results: The SJP group had a relatively low incidence of MACE than the placebo (p < 0.05, odds ratio: 1.916, 95% confidence interval [0.999-3.674]). LVEF was significantly higher in the SJP group than the placebo group on the 360-day follow-up (p < 0.01). SJP had a significant increase score in the SAQ subscale of physical limitation, angina frequency, and treatment satisfaction (p < 0.05). There is no significant difference in the cTNI and CRP level between the two groups. The serum concentration of Fib and cysC in the SJP was significantly decreased compared with the placebo (p < 0.05). The numbers of adverse events between the two groups were not statistically different (p > 0.05). Conclusions: SJP is associated with a reduction in MACE, and an improvement of heart function and quality of life in ACS patients with early PCI, and is probably safe to use.

Prolonged effect associated with inflammatory response observed after exposure to low dose of tritium β-rays

Background: The value of relative biological effectiveness of tritium increases at low dose domain, which results in the suspicion of weighting factor of 1 for tritium after low dose exposure. Thus, present study was carried out to analyze the differences in the cellular responses at early and late period between low dose of tritium β-rays and γ-rays radiation.Methods: MCF-10A cells were exposed to low dose of tritium β-rays or γ-rays, then cellular behaviors, such as DNA double strand breaks (DSBs), apoptosis, reactive oxygen species (ROS) level and inflammatory relevant gene expression were analyzed at early and late period post-irradiation.Results: At early period the elimination of DSB foci produced by HTO is longer than γ-rays. High ROS level and a continual change of cell cycle distribution are observed in HTO radiation group. Based on the results of RNA sequencing, Ingenuity Pathway Analysis (IPA) indicates TNFR1 signaling and production of nitric oxide and ROS are activated as an acute response at 24 h post radiation. Moreover, it also shows a disturbance in cholesterol biosynthesis. The results of 30 days point that there is a lasting active inflammatory response, accompanying with a persistent high expression of relevant cytokines, such as TNF and IL1R.Conclusion: Compared to an acute response induced by γ-rays, a persistent inflammatory response exists in HTO-irradiated cells when cultured for 30 days, which might be related to accumulation of tritium in the form of organically bound tritium (OBT) in cellular DNA or lipids.

[Suggestions for thoracic surgery clinical practice in non-epidemic area of 2019 coronavirus disease]

In this paper, the mechanism of destroying human alveolar epithelial cells and pulmonary tissue by 2019 novel coronavirus (2019-nCoV) was discussed firstly. There may be multiple mechanisms including killing directly the target cells and hyperinflammatory responses. Secondly, the clinical features, CT imaging, short-term and long-term pulmonary function damage of the 2019 coronavirus disease (COVID-19) was analyzed. Finally, some suggestions for thoracic surgery clinical practice in non-epidemic area during and after the epidemic of COVID-19 were provided, to help all the thoracic surgery patients receive active and effective treatment.

Long-term effects of acute cadmium exposure on testis immune privilege

Cadmium (Cd) is a widespread and non-biodegradable pollutant of great concern to human health. This element can affect cellular signal transduction and cell-to-cell interaction in the testis. Immune tolerance towards auto- and alloantigens is an important component of testis immunity. It is involved in spermatogenesis and hormone secretion. Plus, the immune tolerance may help to reveal the changes in testis immunity over a long period after Cd exposure. The current research was aimed at investigating the long-term effects of acute Cd exposure on testis immunity by means of elicitation of testicular immune cell composition shift induced by Cd. Cadmium chloride was intraperitoneally injected at 3 mg Cd/kg to mice. After that testis interstitial cells were stained with surface markers for leukocyte and lymphocyte subpopulations (CD45, CD11b, CD3, CD4, CD8, CD25) and analyzed cytofluorimetrically by week 4, 6, 8 and 12 after Cd administration (Cd group). To identify the delayed effects of cadmium on immune tolerance two groups of animals were subjected to intratesticular allotransplantation of neonatal testis (groups ITT and Cd+ ITT). One of the groups was administered with Cd four weeks before the transplantation (Cd+ITT group). I group served as a control that did not undergo any transplantation or Cd injection. For a better demonstration of the phenomenon of immunological tolerance of the testicles, an additional group (UKT group) was used which got grafts under the kidney capsule (non-immune privileged site).Investigation of the cell population showed that CD45+, CD11b+, CD4+, CD8+ cells were permanently present in testicular interstitial tissue in I group. Intratesticular testis transplantation increased the proportion of CD11b+ but did not have such a pronounced effect on CD8+ cells in ITT group. Moreover, the transplantation elevated CD4+ CD25+ cells known for their immunosuppressive property and promoted graft development by week 2 (histological data). Cd injection resulted in severe inflammation that quenched by week 4 (Cd and Cd+ ITT groups). This time point was chosen for transplantation in Cd+ ITT group. Such Cd pretreatment led to a high CD8+ cell proportion and to the delayed appearance of CD4+ CD25+ cells by week 2 (Cd+ ITTgroup). The finding is consistent with the impairment of graft development in Cd+ ITTgroup pretreated with Cd. Observation suggest that Cd pretreatment was associated with disproportion of interstitial immune cell populations which resulted in the impairment of immunoprotective function of the testis. The impairment of testis immunity showed itself only after several weeks of Cd administration, and only when the recipient testis immunity was provoked by alloantigens of donor testes.

Interlayer Decoupling in 30° Twisted Bilayer Graphene Quasicrystal

Stacking order has a strong influence on the coupling between the two layers of twisted bilayer graphene (BLG), which in turn determines its physical properties. Here, we report the investigation of the interlayer coupling of the epitaxially grown single-crystal 30°-twisted BLG on Cu(111) at the atomic scale. The stacking order and morphology of BLG is controlled by a rationally designed two-step growth process, that is, the thermodynamically controlled nucleation and kinetically controlled growth. The crystal structure of the 30°-twisted bilayer graphene (30°-tBLG) is determined to have quasicrystal-like symmetry. The electronic properties and interlayer coupling of the 30°-tBLG are investigated using scanning tunneling microscopy and spectroscopy. The energy-dependent local density of states with in situ electrostatic doping shows that the electronic states in two graphene layers are decoupled near the Dirac point. A linear dispersion originated from the constituent graphene monolayers is discovered with doubled degeneracy. This study contributes to controlled growth of twist-angle-defined BLG and provides insights on the electronic properties and interlayer coupling in this intriguing system.

Impacts of anthropogenic forcing on source variability of sedimentary organic matter in the Yellow River estuary over the past 60 years

To evaluate changes in the source of sedimentary organic matter (OM) in the Yellow River estuary, a sediment core collected in eastern Laizhou Bay was analyzed for total organic carbon (TOC), stable carbon isotopes of TOC, and biomarkers. The results showed a decreasing trend in terrestrial OM (TOM), but an increasing trend in marine OM (MOM) over the past 60 years. TOM was subdivided into soil OM and plant OM in a three end-member mixing model. The soil OM gradually decreased over the past 60 years, with a significant decline since the 1980s, while the plant OM gradually increased. This reveals that the reduction in TOM was caused mainly by the decreased input of soil OM. The reduced TOM contribution can be attributed primarily to dam construction and a decline in precipitation, whereas the elevated MOM contribution was caused by enhanced marine productivity driven by a rise in nutrient inputs.

Down-regulation of microRNA-31 suppresses hepatic fibrosis induced by carbon tetrachloride

MicroRNA-31 (miR-31) is among the most frequently altered microRNAs in human diseases, and altered expression of miR-31 has been detected in a large variety of diseases types. miR-31 could also regulate a variety of cell functions including hepatic fibrosis. Hepatic stellate cells (HSCs) are regarded as the major cell type involved in hepatic fibrosis. Male BALB/c mice (five mice per group aged 6 weeks) received 200 μL of body weight of carbon tetrachloride (10% CCl4) mixed with olive oil intraperitoneally, and the first dose was doubled. To induce hepatic fibrosis, carbon tetrachloride was injected twice a week for 4, 6, 8, and 10 weeks. Control animals were injected with an equal volume of olive oil at the same time intervals. We found that miR-31 expression and fibrosis-related factors in four hepatic fibrosis stages. However, we noted that inhibition of miR-31 was down-regulated fibrosis-related factor expression in F1–F3 stages, but no F4 stage. Thus, we hypothesize that miR-31 may mediate hepatic fibrosis. In this research, we found that inhibition of miR-31 expression significantly inhibited HSC activation. The biological function of miR-31 during HSC activation might be through targeting hypoxia-inducible factor 1-alpha inhibitor (HIF1AN). Inhibition of miR-31 can reduce the transcription factor activity of hypoxia inducible factor 1 (HIF-1) by targeting the biological effects of HIF1AN with the condition of hypoxia. In later hepatic fibrosis could be rescue combining with inhibition of miR-31 and adding heparin-binding EGF-like growth factor (HBEGF).

KRT15 overexpression predicts poor prognosis in colorectal cancer

Keratin-15 (KRT15) is a type I keratin lacking a defined type II partner and plays a key role in maintaining cytoplasmic stability. Recently, studies have reported that KRT15 was correlated with tumor formation and progression. However, the clinical significance of KRT15 in colorectal cancer is unclear. In this study, we aimed to investigate the expression of KRT15 and its clinical significance in colorectal cancer. KRT15 expression was examined in 98 cases of colorectal cancer and matched adjacent normal tissues by quantificational real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC), respectively. Then, the clinical significance of KRT15 expression was evaluated in colorectal cancer. QRT-PCR results revealed that the mRNA levels of KRT15 in colorectal cancer tissues were significantly higher compared with those in normal tissues (p<0.0001). The rates of KRT15 high-expression in colorectal cancer and normal tissues were 57.1% and 8.9%, respectively, and the difference was statistically significant (p<0.0001). KRT15 high-expression correlated with differentiation, T stage, lymph node metastasis and clinical stage in colorectal cancer (p<0.05). Meanwhile, KRT15 overexpression predicted poor prognosis and could be used as an independent prognostic factor. These data indicate KRT15 is highly expressed in colorectal cancer and may serve as a prognostic biomarker.

A Force-Engineered Lint Roller for Superclean Graphene

Contamination is a major concern in surface and interface technologies. Given that graphene is a 2D monolayer material with an extremely large surface area, surface contamination may seriously degrade its intrinsic properties and strongly hinder its applicability in surface and interfacial regions. However, large-scale and facile treatment methods for producing clean graphene films that preserve its excellent properties have not yet been achieved. Herein, an efficient postgrowth treatment method for selectively removing surface contamination to achieve a large-area superclean graphene surface is reported. The as-obtained superclean graphene, with surface cleanness exceeding 99%, can be transferred to dielectric substrates with significantly reduced polymer residues, yielding ultrahigh carrier mobility of 500 000 cm² V^-1 s^-1 and low contact resistance of 118 Ω µm. The successful removal of contamination is enabled by the strong adhesive force of the activated-carbon-based lint roller on graphene contaminants.

A classification model for lncRNA and mRNA based on k-mers and a convolutional neural network

Background

Long-chain non-coding RNA (lncRNA) is closely related to many biological activities. Since its sequence structure is similar to that of messenger RNA (mRNA), it is difficult to distinguish between the two based only on sequence biometrics. Therefore, it is particularly important to construct a model that can effectively identify lncRNA and mRNA.

Results

First, the difference in the k-mer frequency distribution between lncRNA and mRNA sequences is considered in this paper, and they are transformed into the k-mer frequency matrix. Moreover, k-mers with more species are screened by relative entropy. The classification model of the lncRNA and mRNA sequences is then proposed by inputting the k-mer frequency matrix and training the convolutional neural network. Finally, the optimal k-mer combination of the classification model is determined and compared with other machine learning methods in humans, mice and chickens. The results indicate that the proposed model has the highest classification accuracy. Furthermore, the recognition ability of this model is verified to a single sequence.

Conclusion

We established a classification model for lncRNA and mRNA based on k-mers and the convolutional neural network. The classification accuracy of the model with 1-mers, 2-mers and 3-mers was the highest, with an accuracy of 0.9872 in humans, 0.8797 in mice and 0.9963 in chickens, which is better than those of the random forest, logistic regression, decision tree and support vector machine.

An LTR retrotransposon-derived lncRNA interacts with RNF169 to promote homologous recombination

LTR retrotransposons are abundant repetitive elements in the human genome, but their functions remain poorly understood. Here, we report the function and regulatory mechanism of an ERV-9 LTR retrotransposon-derived lncRNA called p53-regulated lncRNA for homologous recombination (HR) repair 1 (PRLH1) in human cells. PRLH1 is highly expressed in p53-mutated hepatocellular carcinoma (HCC) samples and promotes cell proliferation in p53-mutated HCC cells, and its transcription is promoted by NF-Y and suppressed by p53. Mechanistically, PRLH1 specifically binds to an uncharacterized domain of RNF169 through two GCUUCA boxes in its 5' terminal region to form a DNA repair complex that supplants 53BP1 at double-strand break (DSB) sites and then promotes the initiation of HR repair. Notably, PRLH1 is essential for the stabilization of RNF169, acting as an RNA platform to recruit and assemble HR protein factors. This study characterizes PRLH1 as a novel HR-promoting factor and provides new insights into the function and mechanism of LTR retrotransposon-derived lncRNAs.

Dirac-cone induced gating enhancement in single-molecule field-effect transistors

Using graphene as electrodes provides an opportunity for fabricating stable single-molecule field-effect transistors (FETs) operating at room temperature. However, the role of the unique graphene band structure in charge transport of single-molecule devices is still not clear. Here we report the Dirac-cone induced electrostatic gating effects in single-molecule FETs with graphene electrodes and a solid-state local bottom gate. With the highest occupied molecular orbital (HOMO) as the dominating conduction channel and the graphene leads remaining intrinsic at zero gate voltage, electrostatic gating on the HOMO and the density of states of graphene at the negative gate polarity reinforces each other, resulting in an enhanced conductance modulation. In contrast, gating effects on the HOMO and the graphene states at the positive gate polarity are opposite. Depending on the gating efficiencies, the conductance can decrease, increase or remain almost unchanged when a more positive gate voltage is applied. Our observations can be well understood by a modified single-level model taking into account the linear dispersion of graphene near the Dirac point. Single-molecule FETs with Dirac-cone enhanced gating have shown high performances, with the modulation of a wide range of current over one order of magnitude. Our studies highlight the advantages of using graphene as an electrode material for molecular devices and pave the way for single-molecule FETs toward circuitry applications.

The response of human mesenchymal stem cells to internal exposure to tritium β-rays

There is no doubt that estimating the exposure risk of external and internal low-dose radiation is an imperative issue in radiobiological study. Human mesenchymal stem cells (hMSCs) are multipotent and self-renewing, supporting the regeneration of damaged tissue, including tissue damaged by radiation. However, the responses of hMSCs to internal exposure to radionuclides are still insufficiently understood. In order to evaluate the adverse effects produced by internal exposure to tritiated water (HTO) at a low dose, hMSCs were exposed to 2 × 107 Bq/ml HTO, and the biological effects after the exposure were examined. Apoptosis and DNA double-strand breaks (DSBs) were assayed to analyze the cellular response to the damage induced by HTO. Slight enhancement of apoptosis was found after treatment, except at the dose of 9 mGy. The number of DSBs at 24 h post-irradiation showed that the DNA damage was able to be efficiently repaired by the hMSCs. Moreover, the increasing proportion of the cell population in S phase proved that the persistence of residual γH2AX foci at lower concentrations of HTO was attributable to the secondary production of DSBs in DNA replication. Our work adds to the available data, helping us understand the risk of stem cell transformation due to internal exposure and its correlation with low-dose radiation-induced carcinogenesis.