Managing Excess Lead Iodide with Functionalized Oxo-Graphene Nanosheets for Stable Perovskite Solar Cells.

Stability issues could prevent lead halide perovskite solar cells (PSCs) from commercialization despite it having a comparable power conversion efficiency (PCE) to silicon solar cells. Overcoming drawbacks affecting their long-term stability is gaining incremental importance. Excess lead iodide (PbI2 ) causes perovskite degradation, although it aids in crystal growth and defect passivation. Herein, we synthesized functionalized oxo-graphene nanosheets (Dec-oxoG NSs) to effectively manage the excess PbI2 . Dec-oxoG NSs provide anchoring sites to bind the excess PbI2 and passivate perovskite grain boundaries, thereby reducing charge recombination loss and significantly boosting the extraction of free electrons. The inclusion of Dec-oxoG NSs leads to a PCE of 23.7 % in inverted (p-i-n) PSCs. The devices retain 93.8 % of their initial efficiency after 1,000 hours of tracking at maximum power points under continuous one-sun illumination and exhibit high stability under thermal and ambient conditions.

Incidence and risk factors for febrile neutropenia of patients with diffuse large B-cell lymphoma receiving R-CHOP-21 in China.

OBJECTIVE: Febrile neutropenia (FN) is a serious complication of patients with diffuse large B-cell lymphoma (DLBCL) receiving R-CHOP-21. The prophylactic use of granulocyte colony-stimulating factors (G-CSFs) can significantly reduce the risk of FN. International guidelines recommend G-CSFs for patients receiving chemotherapy with FN risk of 20% or 10 to 20% with defined risk factors. However, there are few studies on the incidence and risk factors of FN in patients with DLBCL receiving R-CHOP-21, especially in patients without primary G-CSF prophylaxis. METHODS: We conducted a retrospective analysis for the clinical data of 103 patients with DLBCL who underwent first R-CHOP-21 without primary G-CSF prophylaxis. The objective of the assessment was the incidence and risk factors of FN after the first chemotherapy cycle. RESULTS: After the first chemotherapy cycle, the incidence of FN was 20.4%. Multivariate analysis showed that age ≥ 65 years, bone marrow involvement, albumin < 35 g/L, and average relative dose intensity ≥ 80% were independent risk factors for FN. According to risk factors, we created a risk score system. The incidence of FN in the low-, intermediate- and high-risk groups was 5.6%, 17.2%, and 61.9%, respectively. CONCLUSION: Our data indicated that R-CHOP-21 itself is associated with a high-risk regiment for FN. We recommend that intermediate/high-risk patients should actively consider primary G-CSF prophylaxis to reduce the incidence of FN after chemotherapy.

Case report: First report of haploidentical allogeneic hematopoietic stem cell transplantation from donors with mild alpha-thalassemia for acute leukemia.

For acute leukemia (AL) with adverse prognostic factors, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the standard care option after the first complete remission. Meanwhile, as the success of haploidentical HSCT (haplo-HSCT), haploidentical donors (HIDs) become a reliable choice. However, there have been no reports on haplo-HSCT from HIDs with mild alpha(α)-thalassemia for AL yet. In the present report, we first describe two cases of successful haplo-HSCT from HIDs with mild α-thalassemia for AL.

A nomogram for predicting the readmission within 6 months after treatment in patients with acute coronary syndrome.

PURPOSE: To explore predictors for readmission within 6 months of ACS patients, and to build a prediction model, and generate a nomogram. METHODS: The retrospective cohort study included 498 patients with ACS in the Second Medical Center of the Chinese People's Liberation Army General Hospital between January 2016 and March 2019. Univariate and multivariate logistic regression with odds ratios (OR) and two-sided 95% confidence interval (CI) analysis were used to investigate predictors for readmission within 6 months. The cohort was randomly divided into training cohort to develop a prediction model, and the validation cohort to validate the model. The receiver operating characteristic curve (ROC) and the calibration curve was used to assess discriminative power and calibration. RESULTS: Eighty-three ACS patients were readmitted within six months, with a readmission rate of 16.67%. Predictors included ACS type, treatment, hypertension, SUA, length of stay, statins, and adverse events occurred during hospitalization were used to form a six-month readmission prediction model for readmission within 6 months in ACS patients. The area under the curve (AUC) of the model was 0.788 (95%CI: 0.735-0.878) and 0.775 (95%CI: 0.686-0.865) in the training cohort and the validation cohort, respectively. Calibration curves showed the good calibration of the prediction model. Decision-curve analyses and clinical impact curve also demonstrated that it was clinically valuable. CONCLUSION: We used seven readily available predictors to develop a prediction model for readmission within six months after treatment in ACS patients, which could be used to identify high-risk patients for ACS readmission.

[Clinical Characteristics and Risk Factors of Invasive Fungal Infections in Acute Leukemia Patients in Tropical Regions].

OBJECTIVE: To analyze the clinical characteristics and risk factors of invasive fungal infection (IFI) occurenced in patients with acute leukemia (AL) during treatment in tropical regions. METHODS: The clinical data of 68 AL patients admitted to the Hainan Hospital of PLA General Hospital from April 2012 to April 2019 was retrospectively analyzed. Logistic regression analysis was used to analyze the factors affecting the occurrence of IFI in AL patients. RESULTS: Among the 68 patients, 44 were acute myeloid leukemia, 24 were acute lymphoblastic leukemia, 39 were male, 29 were female and the median age was 41(13-75) years old. The 68 patients received 242 times of chemotherapy or hematopoietic stem cell transplantation(HSCT), including 73 times of initial chemotherapy or inducting chemotherapy after recurrence, 14 times of HSCT, 155 times of consolidating chemotherapy. Patients received 152 times of anti-fungal prophylaxis, including 77 times of primary anti-fungal prophylaxis and 75 times of secondary anti-fungal prophylaxis. Finally, the incidence of IFI was 31 times, including 24 times of probable diagnosis, 7 times of proven diagnosis, and the total incidence of IFI was 12.8%(31/242), the incidence of IFI in inducting chemotherapy was 24.66%(18/73), the incidence of IFI in HSCT patients was 28.57% (4/14), the incidence of IFI in consolidating chemotherapy was 5.80% (9/155). Multivariate analysis showed that inducting chemotherapy or HSCT, the time of agranulocytosis ≥7 days, risk stratification of high risk were the independent risk factors for IFI in AL patients during treatment in tropical regions. CONCLUSION: The incidence of IFI in patients with AL in the tropics regions is significantly higher than that in other regions at homeland and abroad. Anti-fungal prophylaxis should be given to the patients with AL who have the high risk factors of inducting chemotherapy or HSCT, time of agranulocytosis ≥7 days and risk stratification of high risk.

A radar-like DNA monitor for RNase H-targeted natural compounds screening and RNase H activity in situ detection.

Ribonuclease H is essential for the research and development of complex pathema. The high rigidity and versatility of DNA tetrahedrons means they are often used in biosensing systems. Inspired by "radar" technology, we proposed a radar-like monitor to detect RNase H activity in vitro and in situ by integrating DNA tetrahedral elements. The structure of a radar-like monitor was self-assembled from five customized single nucleic acid strands. Four DNA strands were assembled as DNA tetrahedrons with a long strand labeled by Dabcyl (quencher) at one of the apexes, while the fifth strand (DNA-RNA heterozygous strand) was labeled with a FAM (Fluorophore) hybrid with a long strand. The fluorescence was quenched because the fluorophore and the quencher were very close. In the presence of RNase H, the RNA chain was hydrolyzed and the fluorophore released, resulting in fluorescence recovery. The radar-like monitor was used to detect the RNase H activity in vitro with a detection limit of 0.01 U mL-1. Based on the RNase H activity detection and the inhibitory effect of natural-compounds-targeting RNase H, three inhibitors were obtained among 35 compounds extracted from Panax japonicus. Therefore, the radar-like monitor was successfully used to detect RNase H activity in situ due to the long-term anti-DNase I effect of the RNA/DNA hybrid structure and DNA tetrahedrons structure. Overall, this radar-like monitor can effectively avoid false-positive signals and significantly improve the accuracy, precision, and reliability of detection. It is expected that the development of such an intelligent nano-platform will open the door to cancer diagnosis and treatment in clinical systems.

Interlayer electron modulation in van der Waals heterostructures assembled by stacking monolayer MoS2 onto monolayer graphene with different electron transfer ability.

Achieving tunable optoelectronic properties and clarifying interlayer interactions are key challenges in the development of 2D heterostructures. Herein, we report the feasible modulation of the optoelectronic properties of monolayer MoS2 (1L-MoS2) on three different graphene monolayers with varying ability in extracting electrons. Monolayer oxygen-functionalized graphene (1L-oxo-G, a high amount of oxygen of 60%) with a work function (WF) of 5.67 eV and its lowly oxidized reduction product, namely reduced-oxo-G (1L-r-oxo-G, a low amount of oxygen of 0.1%), with a WF of 5.85 eV serving as hole injection layers significantly enhance the photoluminescence (PL) intensity of MoS2, whereas pristine monolayer graphene (1L-G) with a work function (WF) of 5.02 eV results in PL quenching of MoS2. The enhancement in the PL intensity is due to increase of neutral exciton recombination. Furthermore, 1L-r-oxo-G/MoS2 exhibited a higher increase (5-fold) in PL than 1L-oxo-G/MoS2 (3-fold). Our research can help modulate the carrier concentration and electronic type of 1L-MoS2 and has promising applications in optoelectronic devices.

The effect of the detection of minimal residual disease for the prognosis and the choice of post-remission therapy of intermediate-risk acute myeloid leukemia without FLT3-ITD, NPM1 and biallelic CEBPA mutations.

BACKGROUND: Intermediate-risk acute myeloid leukemia (IR-AML) without FLT3-ITD, NPM1 and biallelic CEBPA mutations (here referred to as NPM1mut-negCEBPAdm-negFLT3-ITDneg AML) is a clinically heterogeneous disease. The optimal post-remission therapy (PRT) is unclear for patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML who achieved first complete response (CR1). This study aims to explore clinical and molecular factors that can help determine the prognosis of those patients and their choice of PRT. METHODS: We retrospectively analyzed 28 patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML who received induction chemotherapy and achieved CR1. For PRT, 17 patients received post-remission chemotherapy (PR-CT) and 11 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT). RESULTS: For patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, multivariate analysis indicated that allo-HSCT and negative minimal residual disease (MRDneg) before PRT were favorable prognostic factors of overall survival (OS) (allo-HSCT, P = 0.002; MRDneg, P = 0.018); whereas relapse was an adverse prognostic factor of OS (P = 0.003). Log-rank analysis showed that allo-HSCT significantly improved their OS and RFS compared with PR-CT (OS, P < 0.001; RFS, P = 001). Otherwise, allo-HSCT improved the OS and RFS of patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, whether they obtained MRDpos or MRDneg before PRT (OS: MRDneg, P = 0.036; MRDpos, P = 0.012; RFS: MRDneg, P = 0.047; MRDpos, P = 0.030). CONCLUSION: For patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, MRDneg before PRT and allo-HSCT were favorable prognostic factors of OS. Whether they obtain MRDneg or not, allo-HSCT is the preferred PRT.

[Single Center Analysis of Bloodstream Infection Clinical Characteristics and Prognosis in Patients with Hematological Malignancies in the Tropics].

OBJECTIVE: To analyze the characteristics, prognosis and risk factors of bloodstream infection in patients with hematological malignancies in the tropics, so as to provide evidence for the prevention and treatment of bloodstream infection. METHODS: The clinical features, blood culture results and prognosis of patients with bloodstream infection in patients with hematological malignancies admitted to Hainan Hospital of PLA General Hospital were retrospectively studied. RESULTS: The most common primary infection site of the 81 patients with hematological malignancies was lung (46.91%), followed by PICC (11.11%). The detection rate of Gram-positive bacteria and Gram-negative bacteria in the blood culture was 60.98% and 30.02%, respectively. Coagulase-negative staphylococci was the most common Gram-positive bacteria resulting in bloodstream infection in our study. Of the Gram-negatives, Klebsiella pneumoniae (34.38%) was predominant, followed by Escherichia coli (18.75%) and Pseudomonas aeruginosa (18.75%). Gram-positive bacteria was highly sensitive (100%) to vancomycin, linezolid and tigecycline. Study showed that Gram-negative bacteria had low sensitive to quinolones, in particular, the resistance rate of Escherichia coli to quinolones was as high as 83.33%. In terms of overall survival (OS), the 30-days OS of patients with Gram-negative and Gram-positive septicemia was 77.42% and 92.00%, respectively. There was no statistically significant difference between the two groups. Multivariate analysis revealed that septic shock (P=0.001, RR=269.27) was an independent risk factor for 30-day mortality, and remission status (P=0.027, RR=0.114) was an independent predictor of a favourable outcome of bloodstream infection in patients with hematological malignancies. CONCLUSION: Gram-positive bacteria are the main pathogens causing bloodstream infections in patients with hematological malignancies in the tropics. Improving the care of PICC is an important measure to reduce the incidence of bloodstream infection in patients with hematological malignancies in the tropics. A correct treatment relieving disease and effective prevention and treatment of septic shock can reduce mortality of patients with bloodstream infection in patients with hematological malignancies in the tropics.

Sensitive RNase A detection and intracellular imaging using a natural compound-assisted tetrahedral DNA nanoprobe.

We report an intracellular imaging and assay nanoplatform for RNase A using a DNA tetrahedron-based fluorescent probe as a substrate. Importantly, a natural compound was used as an RNase A activity stimulator to improve the sensitivity. This platform provides an alternative for the diagnosis and prognosis of RNase A-related diseases and drug screening.

[Clinical Characteristics and Prognosis of U2AF1 Mutation in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the incidence, clinical features of U2AF1 gene mutation in patients with acute myeloid leukemia(AML) and its effect of prognosis. METHODS: A total of 161 patients with AML were enrolled. The second-generation sequencing method was used to detect U2AF1 gene mutation, and the relationship between U2AF1 mutation and clinical features, prognosis was analyzed. RESULTS: The mutation rate of U2AF1 gene in 161 AML patients was 3.73%. The counts of peripheral blood leukocytes and platelets in the U2AF1 gene mutation group were lower than those in the wild type group. The complete response rate of U2AF1 gene mutation group was 66.67%, while that in wild type group was 55.48%, which shows no significant difference between the two groups (P=0.70). The median EFS of wild type group and the mutant group was not reached and reached to 133 days, respectively (P=0.03), while the medium OS in two groups was not reached and reached to 210 days (P=0.01). CONCLUSION: The AML patients with U2AF1 mutation positive have a poor prognosis as compared with the wild type group, which may be a poor prognostic factor for acute myeloid leukemia.

Influence of SiO2 or h-BN substrate on the room-temperature electronic transport in chemically derived single layer graphene.

The substrate effect on the electronic transport of graphene with a density of defects of about 0.5% (0.5%G) is studied. Devices composed of monolayer 0.5%G, partially deposited on SiO2 and h-BN were used for transport measurements. We find that the 0.5%G on h-BN exhibits ambipolar transfer behaviours under ambient conditions, in comparison to unipolar p-type characters on SiO2 for the same flake. While intrinsic defects in graphene cause scattering, the use of h-BN as a substrate reduces p-doping.

Human serum albumin templated MnO2 nanosheets are oxidase mimics for colorimetric determination of hydrogen peroxide and for enzymatic determination of glucose.

This paper reports on a colorimetric assay for H2O2 and glucose. It is based on the use of human serum albumin-templated MnO2 nanosheets that possess oxidase-like activity. They are capable of oxidizing 3,3',5,5'-tetramethylbenzidine (TMB) with oxygen to give a blue product (oxTMB) with an absorbance maximum at 652 nm. When H2O2 is introduced, the MnO2 nanosheets are reduced to Mn(II) ions, and this inhibits the formation of oxTMB. Based on these findings, a colorimetric assay was established for H2O2 that has a 0.56 µM detection limit. If glucose is oxidized by glucose oxidase under formation of H2O2, the nanosheets can be used to quantify H2O2 and thereby to sense glucose. Response is linear in the 0.5 µM to 50 µM glucose concentration range, and the detection limit is 0.32 µM. The method was applied to the determination of glucose in spiked serum samples and gave satisficatory results. Graphical abstract Human serum albumin (HSA) is used as a template for the synthesis of MnO2 nanosheet. These possess oxidase mimicking activity. H2O2 can reduce the nanosheets. The effect is exploited in colorimetric assays for H2O2 and glucose using tetramethylbenzidine (TMB) as a chromogenic substrate.

One-Pot Green Synthesis of Ultrabright N-Doped Fluorescent Silicon Nanoparticles for Cellular Imaging by Using Ethylenediaminetetraacetic Acid Disodium Salt as an Effective Reductant.

Because of excellent photoluminescence properties, robust chemical inertness, and low cytotoxicity of silicon nanoparticles (Si NPs), exploration of their applications in bioimaging is of great interest. Up to date, a method to synthesis Si NPs with high fluorescence quantum yield (QY) is still challenging. This situation limits the further applications of Si NPs. In this work, we report a mild, simple, and green one-pot method to synthesis N-doped fluorescent Si NPs with an ultrahigh QY up to 62%, using ethylenediaminetetraacetic acid disodium salt as an effective reductant. The obtained ultrabright Si NPs have properties such as relative small size (about 2 nm), water dispersibility, robust stability, and biocompatibility. The as-prepared Si NPs were further applied for cellular imaging with satisfactory results, indicating their great potential in bioimaging applications.

Fluorometric determination of nucleic acids based on the use of polydopamine nanotubes and target-induced strand displacement amplification.

The authors describe a fluorometric method for the quantitation of nucleic acids by combining (a) cycled strand displacement amplification, (b) the unique features of the DNA probe SYBR Green, and (c) polydopamine nanotubes. SYBR Green undergoes strong fluorescence enhancement upon intercalation into double-stranded DNA (dsDNA). The polydopamine nanotubes selectively adsorb single-stranded DNA (ssDNA) and molecular beacons. In the absence of target DNA, the molecular beacon, primer and SYBR Green are adsorbed on the surface of polydopamine nanotubes. This results in quenching of the fluorescence of SYBR Green, typically measured at excitation/emission wavelengths of 488/518 nm. Upon addition of analyte (target DNA) and polymerase, the stem of the molecular beacon is opened so that it can bind to the primer. This triggers target strand displacement polymerization, during which dsDNA is synthesized. The hybridized target is then displaced due to the strand displacement activity of the polymerase. The displaced target hybridizes with another molecular beacon. This triggers the next round of polymerization. Consequently, a large amount of dsDNA is formed which is detected by addition of SYBR Green. Thus, sensitive and selective fluorometric detection is realized. The fluorescent sensing strategy shows very good analytical performances towards DNA detection, such as a wide linear range from 0.05 to 25 nM with a low limit of detection of 20 pM. Graphical abstract Schematic of a fluorometric strategy for highly sensitive and selective determination of nucleic acids by combining strand displacement amplification and the unique features of SYBR Green I (SG) and polydopamine nanotubes.

Synthesis of Luminescent Carbon Dots with Ultrahigh Quantum Yield and Inherent Folate Receptor-Positive Cancer Cell Targetability.

Carbon dots (CDs) have a wide range of applications in chemical, physical and biomedical research fields. We are particularly interested in the use of CDs as fluorescence nanomaterials for targeted tumor cell imaging. One of the important aspects of success is to enhance the fluorescence quantum yields (QY) of CDs as well as increase their targetability to tumor cells. However, most of the reported CDs are limited by relative low QY. In the current study, for the first time, one-step synthesis of highly luminescent CDs by using folic acid (FA) as single precursor was obtained in natural water through hydrothermal method. The as-prepared CDs exhibited QY as high as 94.5% in water, which is even higher than most of organic fluorescent dyes. The obtained CDs showed excellent photoluminescent activity, high photostability and favorable biocompatibility. The FA residuals in CDs led to extraordinary targetability to cancer cells and promoted folate receptor-mediated cellular uptake successfully, which holds a great potential in biological and bioimaging studies.

Nitrogen-doped Carbon Dots Mediated Fluorescent on-off Assay for Rapid and Highly Sensitive Pyrophosphate and Alkaline Phosphatase Detection.

In this report, a novel fluorescent sensing platform using nitrogen-doped carbon dots (N-CDs) as probes for fluorescence signal transmission has been designed for the detection of significant biomolecules pyrophosphate (PPi) and alkaline phosphatase (ALP). The high fluorescent N-CDs could be selectively quenched by Cu2+, and recovered by the addition of PPi because PPi preferentially binds to Cu2+. Once ALP was introduced into the system, ALP can specifically hydrolyze PPi into Pi, the intense fluorescence of N-CDs could be quenched again due to the recombination of the as-released Cu2+ with N-CDs. So, fluorescence of N-CDs is regulated by an ALP-triggered reaction. Based on this strategy, we demonstrated that N-CDs could serve as a very effective fluorescent sensing platform for label-free, sensitive and selective detection of PPi and ALP with low detection limit of 0.16 µM and 0.4 U/L for PPi and ALP, respectively. Moreover, the assay time is just around 0.5 min for PPi and 30 min for ALP. This developed strategy shows remarkable advantages including sensitive, rapid, simple, convenient, and low-cost and so forth. Furthermore, this method was also successfully applied to monitor ALP in human serum, which indicates its great potential for practical applications in biological and clinical diagnosis.

A rapid fluorescence "switch-on" assay for glutathione detection by using carbon dots-MnO2 nanocomposites.

Glutathione (GSH) serves many cellular functions and plays crucial roles in human pathologies. Simple and sensitive sensors capable of detecting GSH would be useful tools to understand the mechanism of diseases. In this work, a rapid fluorescence "switch-on" assay was developed to detect trace amount of GSH based on carbon dots-MnO2 nanocomposites, which was fabricated through in situ synthesis of MnO2 nanosheets in carbon dots colloid solution. Due to the formation of carbon dots-MnO2 nanocomposites, fluorescence of carbon dots could be quenched efficiently by MnO2 nanosheeets through fluorescence resonance energy transfer (FRET). However, the presence of GSH would reduce MnO2 nanosheets to Mn(2+) ions and subsequently release carbon dots, which resulted in sufficient recovery of fluorescent signal. This proposed assay demonstrated highly selectivity toward GSH with a detection limit of 300nM. Moreover, this method has also shown sensitive responses to GSH in human serum samples, which indicated its great potential to be used in disease diagnosis. As no requirement of any further functionalization of these as-prepared nanomaterials, this sensing system shows remarkable advantages including very fast and simple, cost-effective as well as environmental-friendly, which suggest that this new strategy could serve as an efficient tool for analyzing GSH level in biosamples.