Ultrasound-responsive Bi2MoO6-MXene heterojunction as ferroptosis inducers for stimulating immunogenic cell death against ovarian cancer.

BACKGROUND: Ovarian cancer (OC) has the highest fatality rate among all gynecological malignancies, necessitating the exploration of novel, efficient, and low-toxicity therapeutic strategies. Ferroptosis is a type of programmed cell death induced by iron-dependent lipid peroxidation and can potentially activate antitumor immunity. Developing highly effective ferroptosis inducers may improve OC prognosis. RESULTS: In this study, we developed an ultrasonically controllable two-dimensional (2D) piezoelectric nanoagonist (Bi2MoO6-MXene) to induce ferroptosis. A Schottky heterojunction between Bi2MoO6 (BMO) and MXene reduced the bandgap width by 0.44 eV, increased the carrier-separation efficiency, and decreased the recombination rate of electron-hole pairs under ultrasound stimulation. Therefore, the reactive oxygen species yield was enhanced. Under spatiotemporal ultrasound excitation, BMO-MXene effectively inhibited OC proliferation by more than 90%, induced lipid peroxidation, decreased mitochondrial-membrane potential, and inactivated the glutathione peroxidase and cystathionine transporter protein system, thereby causing ferroptosis in tumor cells. Ferroptosis in OC cells further activated immunogenic cell death, facilitating dendritic cell maturation and stimulating antitumor immunity. CONCLUSION: We have succeeded in developing a highly potent ferroptosis inducer (BMO-MXene), capable of inhibiting OC progression through the sonodynamic-ferroptosis-immunogenic cell death pathway.

Severe flood modulates the sources and age of dissolved organic carbon in the Yangtze River Estuary.

Floods in global large rivers modulate the transport of dissolved organic carbon (DOC) and estuarine hydrological characteristics significantly. This study investigated the impact of a severe flood on the sources and age of DOC in the Yangtze River Estuary (YRE) in 2020. Comparing the flood period in 2020 to the non-flood period in 2017, we found that the flood enhanced the transport of young DOC to the East China Sea (ECS), resulting in significantly enriched Δ14C-DOC values. During the flood period, the proportion of modern terrestrial organic carbon (OC) was significantly higher compared to the non-flood period. Conversely, the proportion of pre-aged sediment OC was significantly lower during the flood period. The high turbidity associated with the flood facilitated rapid transformation and mineralization of sedimentary and fresh terrestrial OC, modifying the sources of DOC. The flux of modern terrestrial OC transported to the ECS during the flood period was 1.58 times higher than that of the non-flood period. These findings suggest that floods can modulate the sources and decrease the age of DOC, potentially leading to increased greenhouse gas emissions. Further research is needed to understand the long-term impacts of floods on DOC dynamics in global estuaries.

Sex-specific impacts of thimerosal on the behaviors and brain monoaminergic systems in zebrafish (Danio rerio).

Thimerosal (THI) is the most widely used form of organic mercury in pharmaceutical and personal care products, and has become a major source of ethylmercury pollution in aquatic ecosystems. However, knowledge about its potential risk to aquatic species is limited. In this study, zebrafish were exposed to THI for 7 days, and variations in their behavioral traits, brain monoaminergic neurotransmitter contents, and related gene expression were investigated. After the 7-day exposure, THI reduced locomotor activity and thigmotaxis in males but not females. Exposure to THI increased the social interaction between females but decreased that between males. The THI exposure also significantly reduced the serotonin (5-HT), 5-hydroxyindoleacetic acid, dopamine (DA), and 3,4-dihydroxyphenylacetic acid contents in the brain of males, but only significantly decreased the DA content in females. Correlation analysis revealed that the neurochemical alterations in the brain of zebrafish play critical roles in the behavioral abnormalities induced by THI exposure. Moreover, THI also significantly altered the expression of some genes associated with the synthesis, metabolism, and receptor binding of 5-HT and DA in the brain of zebrafish. The differences in these gene expressions between female and male zebrafish exposed to THI seem to be an important mechanism underlying their sex-specific responses to this chemical. This is the first report on the sex-specific effects of THI on behaviors and brain monoaminergic neurotransmitter contents in zebrafish, which can further improve our understanding of its toxic effects on teleost.

Automatic high-throughput and non-invasive selection of sperm at the biochemical level.

BACKGROUND: Sperm selection, a key step in assisted reproductive technology (ART), has long been restrained at the preliminary physical level (morphology or motility); however, subsequent fertilization and embryogenesis are complicated biochemical processes. Such an enormous "gap" poses tough problems for couples dealing with infertility, especially patients with severe/total asthenozoospermia . METHODS: We developed a biochemical-level, automatic-screening/separation, smart droplet-TO-hydrogel chip (BLASTO-chip) for sperm selection. The droplet can sense the pH change caused by sperm's respiration products and then transforms into a hydrogel to be selected out. FINDINGS: The BLASTO-chip system can select biochemically active sperm with an accuracy of over 90%, and its selection efficiency can be flexibly tuned by nearly 10-fold. All the substances in the system were proven to be biosafe via evaluating mice fertilization and offspring health. Live sperm down to 1% could be enriched by over 76-fold to 76%. For clinical application to patients with severe/total asthenozoospermia, the BLASTO-chip could select live sperm from human semen samples containing 10% live but 100% immotile sperm. The rates of fertilization, cleavage, early embryos, and blastocysts were drastically elevated from 15% to 70.83%, 10% to 62.5%, 5% to 37.5%, and 0% to 16.67%, respectively. CONCLUSIONS: The BLASTO-chip represents a real biochemical-level technology for sperm selection that is completely independent of sperm's motility. It can be a powerful tool in ART, especially for patients with severe/total asthenozoospermia. FUNDING: This work was funded by the Ministry of Science and Technology of China, the Ministry of Education of China, and the Shenzhen-Hong Kong Hetao Cooperation Zone.

Two-Dimensional Sc2CCl2/XSe2(X=Mo, Pt) van der Waals Heterojunctions: Promising Photocatalytic Hydrogen Evolution Materials.

In the field of photocatalysis, new heterojunction materials are increasingly explored to achieve efficient energy conversion and environmental catalysis under visible light and sunlight. This paper presents a study on two newly constructed two-dimensional van der Waals heterojunctions, Sc2CCl2/MoSe2 and Sc2CCl2/PtSe2, using density-functional theory. The study includes a systematic investigation of their geometrical structure, electronic properties, and optical properties. The results indicate that both heterojunctions are thermodynamically, kinetically, and mechanically stable. Additionally, Bader charge analysis reveals that both heterojunctions exhibit typical type II band properties. However, the band gap of the Sc2CCl2/MoSe2 heterojunction is only 1.18 eV, which is insufficient to completely cross the reduction and oxidation (REDOX) potential of 1.23 eV, whereas the band gap of Sc2CCl2/PtSe2 heterojunction is 1.49 eV, which is theoretically capable for water decomposition. The subsequent calculation of the Sc2CCl2/PtSe2 heterojunction demonstrate excellent hole carrier mobility and high efficiency light absorption in the visible light range, facilitating the separation of photogenerated electrons and holes. More importantly, Sc2CCl2/PtSe2 vdW type II heterojunction can achieve full water decomposition from pH 1 to pH 4, and its thermodynamic feasibility is confirmed by Gibbs free energy results. The aim of this study is to develop materials and analyses that will result in optoelectronic devices that are more efficient, stable, and sustainable.

Label-free colorimetric detection platform based on catalytic hairpin self-assembly and G-quadruplex/hemin DNAzyme for comprehensive biomarker profiling.

The expression level of human apurinic/apyrimidinic endonuclease 1 (APE1) is closely associated with the onset of various diseases, establishing it as a crucial clinical biomarker and a target in anti-cancer efforts. This study accomplished colorimetric and visual detection of APE1 by harnessing its endonuclease activity through catalytic hairpin self-assembly (CHA) and G-quadruplex/hemin DNAzyme. Optimization of the freedom degrees of the G-rich sequence significantly improved the detection performance of the strategy by influencing DNAzyme formation. Additionally, we replaced the signal reporting system with a molecular beacon to develop a fluorescence detection strategy, which served as an extension of the signal amplification system for validation and signal readout. The fluorescent probe method achieved a detection limit of 3.37 × 10-4 U/mL, while the colorimetric method yielded a detection limit of 6.5 × 10-3 U/mL, with a linear range spanning from 0.01 to 0.25 U/mL. Subsequently, the colorimetric approach effectively assessed APE1 activity in biological samples and facilitated the screening of APE1 activity inhibitors. Furthermore, this CHA/G-quadruplex/hemin DNAzyme strategy was adapted for the colorimetric detection of adenosine, showcasing its broad applicability across various biomarkers. The developed colorimetric analytical strategy represents a pivotal biosensing platform for diagnosing and treating diseases.

A bicomponent synergistic MoxW1-xS2/aluminum nitride vdW heterojunction for enhanced photocatalytic hydrogen evolution: a first principles study.

The coupling of two-dimensional van der Waals heterojunctions is an effective way to achieve photocatalytic hydrogen production. This paper designs the MoxW1-xS2/AlN (x = 0, 0.25, 0.5, 0.75, 1) van der Waals heterojunction as a possible photocatalytic material. By using first-principles calculations, the effects of different Mo/W ratios on the band gap and photocatalytic hydrogen production performance of heterojunctions were investigated. The results show that the heterojunction is a direct Z-scheme photocatalyst and can achieve overall water splitting. By calculating the absorption spectrum, it is found that the heterojunction has a wider visible light absorption range when the bimetal is added, and there is still a strong absorption peak at 615 nm. With the increase of the Mo atom ratio, the absorption spectrum is red-shifted. The Gibbs free energy of the two-component Mo0.5W0.5S2/AlN heterojunction is only -0.028 eV. Our work provides a new perspective for the modification of 2D transition metal dichalcogenide photocatalytic heterojunctions.

lncRNA UCA1 promotes tumor progression by targeting SMARCD3 in cervical cancer.

Long noncoding RNA urothelial carcinoma associated 1 (UCA1) has been identified as a key molecule in human cancers. However, its functional implications remain unspecified in the context of cervical cancer (CC). This research aims to identify the regulatory mechanism of UCA1 in CC. UCA1 was identified through microarray and confirmed through a quantitative real-time polymerase chain reaction. Proteins that bind with UCA1 were recognized using RNA pull-down assays along with RNA immunoprecipitation. Ubiquitination assays and coimmunoprecipitation were performed to explore the molecular mechanisms of the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily d, member 3 (SMARCD3) downregulated in CC. The effects of UCA1 and SMARCD3 on the progression of CC were investigated through gain- and loss-of-function assays and xenograft tumor formation in vivo. In this study, UCA1 was found to be upregulated in CC cells as well as in human plasma exosomes for the first time. Functional studies indicated that UCA1 promotes CC progression. Mechanically, UCA1 downregulated the SMARCD3 protein stabilization by promoting SMARCD3 ubiquitination. Taken together, we revealed that the UCA1/SMARCD3 axis promoted CC progression, which could provide a new therapeutic target for CC.

Ultrasensitive and Quantitative DNA Methylation Detection Method Based on the MutS Protein.

DNA methylation is closely related to cancer. It is generally accepted that DNA methylation detection is crucial in cancer diagnosis, prognosis, and treatment monitoring. Therefore, there is an urgent demand for developing a simple, rapid, highly sensitive, and highly specific methylation detection method to detect DNA methylation at specific sites quantitatively. In this work, we introduce a DNA methylation detection method based on MutS and methylation-specific PCR, named MutS-based methylation-specific PCR (MB-MSP), which has the advantages of simplicity, speed, high specificity, sensitivity, and broad applicability. Utilizing the MutS's ability to bind mismatched base pairs, we inhibit not only the amplification of unmethylated DNA but also nonspecific primer amplification. We achieved a detection sensitivity of 0.5% for the methylated genes of ACP1, CLEC11A, and SEPT9 by MB-MSP. It has a good linear relationship and a detection time of only 1.5 h. To validate the feasibility of the MB-MSP method in clinical application, we conducted methylation detection on plasma-circulating tumor DNA samples from 10 liver cancer patients and 5 healthy people, achieving a 100% accuracy rate. In conclusion, MB-MSP, as a novel and reliable DNA methylation detection tool, holds significant application value and potential for advancing early cancer diagnosis.

Two-dimensional AlN/TMO van der Waals heterojunction as a promising photocatalyst for water splitting driven by visible light.

In this study, the photocatalytic properties of AlN/TMO heterojunctions formed by coupling MoO2 and WO2 of transition metal oxides with AlN are studied in detail using first-principles calculations with the aim of finding efficient and low-cost photocatalysts for water splitting to produce hydrogen to reduce environmental pollution. The AIMD, phonon spectrum, and elastic constants demonstrated the thermodynamic, kinetic, and mechanical stabilities of the AlN/TMO heterojunction. The results showed that the AlN/MoO2 (1.55 eV) and AlN/WO2 (1.99 eV) heterojunctions have typical type-II energy band arrangements, which can effectively promote the separation of photogenerated electrons and hole pairs. Meanwhile, the AlN/MoO2 heterojunction showed excellent carrier mobilities (electron, 250.05 cm2 V-1 S-1 and hole, 45 467.07 cm2 V-1 S-1), which greatly exceeded those of each component. The AlN/WO2 heterojunction showed an excellent HER (-0.07 eV) performance, which was close to the expected value. For the AlN/WO2 heterojunction, a suitable band gap value, excellent HER, and other properties indicated that it has the potential to become a new candidate for photocatalytic water splitting. Our study enriches the theoretical research of transition metal oxide materials and wide-band gap materials by providing a reference direction for the design of reasonably high-quality photocatalysts.

Highly-sensitive and homogenous detection of 8-oxoguanine based DNA oxidative damage by a CRISPR-enhanced structure-switching aptamer assay.

8-oxoguanine (8-oxoG) based DNA damage is the most common type of DNA damage which greatly affect gene expression. Therefore, accurate quantification of 8-oxoG based DNA damage is of high clinical significance. However, current methods for 8-oxoG detection struggle to balance convenience, low cost, and sensitivity. Herein, we have proposed and investigated the shortened crRNA mode of CRISPR-Cas12a system and greatly enhanced its signal-to-noise ratio. Taking advantages of the shortened crRNA mode, we further developed a CRISPR-enhanced structure-switching aptamer assay (CESA) for 8-oxoG. The analytical performance of CESA was thoroughly investigated via detecting free 8-oxoG and 8-oxoG on gDNA. The CESA displayed impressive sensitivity for free 8-oxoG, with detection and quantification limits of 32.3 pM and 0.107 nM. These limits modestly rose to 64.5 pM and 0.215 nM when examining 8-oxoG on gDNA. To demonstrate the clinical practicability and significance of the CESA system, we further applied it to measuring 8-oxoG levels in 7 plasma samples (Cervical carcinoma, 11.87 ± 0.69 nM VS. Healthy control, 2.66 ± 0.42 nM), 24 seminal plasma samples (Asthenospermia, 22.29 ± 7.48 nM VS. Normal sperm, 9.75 ± 3.59 nM), 10 breast-tissue gDNA samples (Breast cancer, 2.77 ± 0.63 nM/µg VS. Healthy control, 0.41 ± 0.09 nM/µg), and 24 sperm gDNA samples (Asthenospermia, 28.62 ± 4.84 VS. Normal sperm, 16.67 ± 3.31). This work not only proposes a novel design paradigm of shortened crRNA for developing CRISPR-Cas12a based biosensors but also offers a powerful tool for detecting 8-oxoG based DNA damage.

Ultra-sensitive biosensor based on CRISPR-Cas12a and Endo IV coupled DNA hybridization reaction for uracil DNA glycosylase detection and intracellular imaging.

As an essential biomarker associated with various diseases, Uracil-DNA Glycosylase (UDG) detection is vital for disease diagnosis, treatment selection, and prognosis assessment. In recent years, the signal amplification effect of the CRISPR-Cas12a trans-cleaved single-stranded DNA probe has provided an available strategy for constructing highly sensitive biosensors. However, its superior trans-cleavage activity has become a "double-edged sword" for building biosensors that can amplify the target signal while also amplifying the leakage signal, causing out of control. Therefore, the construction of structurally simple, extremely low-background, highly sensitive CRISPR-Cas12a-based biosensors is an urgent bottleneck problem in the field. Here, we applied CRISPR-Cas12a with a DNA hybridization reaction to develop a simple, rapid, low background, and highly sensitive method for UDG activity detection. It has no PAM restriction and the detection limit is as low as 2.5 × 10-6 U/mL. As far as we know, this method is one of the most sensitive methods for UDG detection. We also used this system to analyze UDG activity in tumor cells (LOD: 1 cell/uL) and to evaluate the ability to screen for UDG inhibitors. Furthermore, we verified the possibility of intracellular UDG activity imaging by transfecting the biosensors to the cells. We believe this novel sensor has good clinical application prospects and will effectively broaden the application space of CRISPR-Cas12a.

A universal and sensitive gene mutation detection method based on CRISPR-Cas12a.

Single nucleotide mutations are highly related to the occurrence and development of cancer. The development of simple single nucleotide mutation detection methods with high sensitivity and specificity has great clinical significance for the prevention, diagnosis, treatment and prognosis evaluation of cancer. In recent years, CRISPR/Cas12a has been developed as a highly sensitive, simple and fast tool for nucleic acid detection. However, the specificity and universality of current detection methods based on it are still insufficient, so their clinical applications are limited. Herein, we developed a simple and rapid single nucleotide mutation detection method based on CRISPR/Cas12a system. This method not only solves the problem of PAM sequence restriction of CRISPR/Cas12a, but also significantly improves the specificity of CRISPR/Cas12a for single nucleotide mutation and greatly improves the sensitivity. We detected three clinically significant mutations, PTEN R130Q, BRAF V600E, and TP53 R248W, with a detection limit of 0.1%. Finally, we further verified the clinical practicability of this method. We selected TP53 R248W mutation site for testing. The accuracy of testing results for 10 clinical samples was as high as 100%. In conclusion, the detection method of specific PCR combined with CRISPR/Cas12a is simple, rapid, universal and highly sensitive. We believe that this method has promising application prospects in clinical diagnosis of cancer.

A universal and specific RNA biosensor via DNA circuit-mediated PAM-independent CRISPR/Cas12a and PolyA-rolling circle amplification.

Point of care testing (POCT) has important clinical significance for the diagnosis and prognosis evaluation of diseases. At present, the biosensor based on CRISPR/Cas12a has become a powerful diagnostic tool due to its high sensitivity. However, CRISPR/Cas12a requires PAM sequence to recognize target double strand and only can recognize specific sequence, so it is not universal. The current RNA detection techniques either lack consideration for specificity and universality, are expensive and difficult, or both. Therefore, it is crucial to create a CRISPR/Cas12a-based RNA detection system that is easy to use, cheap, specific, and universal in order to further its use in molecular diagnostics. Here, we established a DNA circuit-mediated PAM-independent CRISPR/Cas12a coupled PolyA-rolling circle amplification for RNA detection biosensor, namely DCPRBiosensor. The DCPRBiosensor not only functions as a simple, inexpensive, and highly sensitive RNA detection sensor, but it also boasts innovative specificity and universality features. More importantly, DCPRBiosensor removes the PAM restriction of CRISPR/Cas12a. The DCPRBiosensor's detection limit reached 100 aM and it had a linear relationship between 100 aM and 10 pM. We detected four piRNAs to verify the universality and stability of DCPRBiosensor. Then, we verified that DCPRBiosensor has good discrimination ability for single-base mismatch. Finally, we successfully detected piRNA in DLD-1 and HCT-116 cells and urine mixed samples within 4.5 h. In conclusion, we believe that DCPRBiosensor will have a substantial impact on both the development of CRISPR/as12a's applications and the investigation of the clinical value of piRNA.

A Novel ECG-Derived Respiration Method Combining Frequency-Domain Feature and Interacting Multiple Model Smoother.

OBJECTIVE: ECG-derived respiration (EDR) is a low-cost and productive means for capturing respiratory activity. In particular, as the primary procedure in some cardiorespiratory-related studies, the quality of EDR is decisive for the performance of subsequent analyses. APPROACH: In this paper, we proposed a novel EDR method based on the feature derived from the first moment (mean frequency) of the power spectrum (FMS). After obtaining the EDR signal from the feature, we introduced the Interacting Multiple Model (IMM) smoother to enhance the similarity of the EDR signal to the reference respiration. The assessment of the approach consisted of two steps: 1) the performance of extracted feature was verified against R-peak misalignment and noise. 2) the enhancement of IMM smoother to EDR waveforms was evaluated based on waveform correlation and respiratory rate estimation. All the assessments were conducted under the Fantasia database and Drivers database. RESULTS: The FMS improved robustness against R peak offsets compared to most established feature-based EDR algorithms, but a slight 5% improvement of waveform correlation against RR interval-based feature under accurate R peaks. The IMM smoother performed similarly with the Kalman filter in the static database but realized the enhancement of some extent of the EDR waveform in the ambulatory database. SIGNIFICANCE: The proposed method investigated frequency domain mapping of ECG morphological changes caused by respiratory modulation and explained the EDR signal as a non-stationary time series, which provided a direction of better fitting the natural respiration process and enhancing the EDR waveform.

Identification of EMT-associated LncRNA Signature for Predicting the Prognosis of Patients with Endometrial Cancer.

BACKGROUND: Endometrial cancer (EC) is one of the most normal malignancies globally. Growing evidence suggests epithelial-mesenchymal transition (EMT) related markers are closely correlated with poor prognosis of EC. However, the relationship between multiple EMT-associated long non-coding RNAs (lncRNAs) and the prognosis of EC has not yet been studied. METHODS: The transcriptome data and clinical information of EC cases were obtained from The Cancer Genome Atlas (TCGA). Then, we identified differentially expressed EMT-associated lncRNAs between tumor and normal tissue. Univariate cox regression analysis and multivariate stepwise Cox regression analysis were applied to identify EMT-associated lncRNAs related to overall survival (OS). Kaplan-Meier curve, receiver operating characteristic (ROC), nomograms and multi-index ROC curves were further established to evaluate the performance of the prognostic signature. In addition, we also investigated the distribution of immune cell characteristics, sensitivity to immune checkpoint inhibitor (ICI) and chemotherapeutics, and tumor mutation burden (TMB) between high- and low-risk scores predicated on a prognostic model. RESULTS: We established nine EMT-associated lncRNA signatures to predict the OS of EC, the area under the ROC curve (AUC) of the risk score has better values than other clinical characteristics, indicating the accuracy of the prognostic signature. As revealed by multivariate Cox regression, the prognosis model independently predicted EC prognosis. Moreover, the signature and the EMTassociated lncRNAs showed significant correlations with other clinical characteristics,including. Multi-index ROC curves for estimating 1-, 3- and 5-year overall survival (OS) of EC patients showed good predictive accuracy with AUCs of 0.731, 0.791, and 0.782, respectively. The highrisk group had specific tumor immune infiltration, insensitive to ICI, higher chemotherapeutics sensitivity and higher expression of TP53 mutation. Finally, the five lncRNAs of signature were further verified by qRT-PCR. CONCLUSION: We constructed an EMT-associated lncRNA signature that can predict the prognosis of EC effectively, and the prognostic signature also played an essential role in the TME; thus, the establishment of an EMT-associated lncRNA signature may provide new perspectives for the treatment of EC.

A versatile and convenient tool for regulation of DNA strand displacement and post-modification on pre-fabricated DNA nanodevices.

Toehold-mediated strand displacement and its regulatory tools are fundamental for DNA nanotechnology. However, current regulatory tools all need to change the original sequence of reactants, making the regulation inconvenient and cumbersome. More importantly, the booming development of DNA nanotechnology will soon promote the production of packaged and batched devices or circuits with specified functions. Regarding standardized, packaged DNA nanodevices, access to personalized post-modification will greatly help users, whereas none of the current regulatory tools can provide such access, which has greatly constrained DNA nanodevices from becoming more powerful and practical. Herein, we developed a novel regulation tool named Cap which has two basic functions of subtle regulation of the reaction rate and erasability. Based on these functions, we further developed three advanced functions. Through integration of all functions of Cap and its distinct advantage of working independently, we finally realized personalized tailor-made post-modification on pre-fabricated DNA circuits. A pre-fabricated dual-output DNA circuit was successfully transformed into an equal-output circuit, a signal-antagonist circuit and a covariant circuit according to our requirements. Taken together, Cap is easy to design and generalizable for all strand displacement-based DNA nanodevices. We believe the Cap tool will be widely used in regulating reaction networks and personalized tailor-made post-modification of DNA nanodevices.

PAM-independent ultra-specific activation of CRISPR-Cas12a via sticky-end dsDNA.

Although CRISPR-Cas12a [clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 12a] combining pre-amplification technology has the advantage of high sensitivity in biosensing, its generality and specificity are insufficient, which greatly restrains its application range. Here, we discovered a new targeting substrate for LbaCas12a (Lachnospiraceae bacterium Cas12a), namely double-stranded DNA (dsDNA) with a sticky-end region (PAM-SE+ dsDNA). We discovered that CRISPR-Cas12a had special enzymatic properties for this substrate DNA, including the ability to recognize and cleave it without needing a protospacer adjacent motif (PAM) sequence and a high sensitivity to single-base mismatches in that substrate. Further mechanism studies revealed that guide RNA (gRNA) formed a triple-stranded flap structure with the substrate dsDNA. We also discovered the property of low-temperature activation of CRISPR-Cas12a and, by coupling with the unique DNA hybridization kinetics at low temperature, we constructed a complete workflow for low-abundance point mutation detection in real samples, which was fast, convenient and free of single-stranded DNA (ssDNA) transformation. The detection limits were 0.005-0.01% for synthesized strands and 0.01-0.05% for plasmid genomic DNA, and the mutation abundances provided by our system for 28 clinical samples were in accordance with next-generation sequencing results. We believe that our work not only reveals novel information about the target recognition mechanism of the CRISPR-Cas12a system, but also greatly broadens its application scenarios.

Laparoscopic vs. open procedure for intermediate­ and high­risk endometrial cancer: a minimum 4-year follow-up analysis.

BACKGROUND: The long-term oncologic outcomes after laparoscopic and open procedures for patients with intermediate­ and high­risk endometrial cancer (EC) remain unclear. Accordingly, laparoscopy cannot still be recommended as the standard choice for intermediate­ and high­risk EC. This retrospective study aimed to assess the perioperative and long-term oncologic outcomes of laparoscopy and open surgery in patients with intermediate- and high­risk ECs within a minimum 4-year follow-up. METHODS: We included 201 patients who underwent laparoscopic or open procedures for intermediate­ and high­risk EC between 2010 and 2017. Between-procedure comparisons of perioperative and oncological outcomes were performed using the independent t-test or Pearson's chi-squared test and the Kaplan-Meier method, respectively. RESULTS: Finally, there were 136 intermediate­ and 65 high­risk endometrial tumors in the laparoscopic and open groups, respectively. There were no between-group differences in all baseline characteristics. Compared with the open group, the laparoscopic group had a significantly longer mean operating time (p = 0.005) and a lower mean estimated blood loss (EBL) (p = 0.031). There was a higher possibility of postoperative complication in the open group than in the laparoscopic group (p = 0.048). There were no significant between-group differences in pathological outcomes as well as the recurrence-free survival and overall survival rates (p = 0.626 and p = 0.148, respectively). CONCLUSIONS: Among patients with intermediate­ and high­risk EC, laparoscopic surgery has an advantage over the open surgery in reducing EBL and the rate of postoperative complications without weakening the oncological control. There were no between-procedure differences in the recurrence-free and overall survival rates.

A sensitive and specific nano-vehicle based on self-amplified dual-input synthetic gene circuit for intracellular imaging and treatment.

Synthetic genetic circuits (SGCs) that sense multiple biomarkers and respond intelligently provide a powerful tool for intracellular biosensing. The SGC is usually loaded into the nanoscale liposomes to build functional intracellular nano-vehicles, widely applied in diagnosing and treating diseases. However, because the system needs to identify multiple targets to activate, the sensitivity will be inevitably reduced though the specificity is improved, leading to false-negative results in diagnosis and low killing dosage in treatment. Such compromise between specificity and sensitivity has been a bottleneck problem for the field. We innovatively invented the self-amplified dual-input (SADI) SGC@liposome nano-vehicle and broke the bottleneck problem above. It provides multiple sites for regulating sensitivity at both coarse and fine levels, allowing researchers to conveniently balance the sensitivity and specificity according to the application and instrumental setups. In recognizing ovarian cancer cells, the nano-vehicle could enhance the sensitivity by nearly 10-fold, and the specificity remained at high levels of 16-fold. We also changed the output fluorescent signal to output effectors such as apoptosis regulator (BAX) and proliferation-inhibiting protein (p21) and demonstrated the application range. Furthermore, we verified the generality of the system by applying it to target different cells. We believe it will provide a convenient and powerful tool for biosensors and targeted therapy.