Covalent‐organic frameworks (COFs) have been recognized as a new type of promising photocatalysts for hydrogen evolution. To investigate how different functional groups attached in the backbone of ...COFs affect the overall photocatalytic H2 evolution, for the first time, we selected and synthesized a series of ketoenamine‐based COFs with the same host framework as model system. It includes TpPa−COF−X (X=−H, −(CH3)2, and −NO2) with three different groups attached in the backbone of TpPa−COF. We systematically investigated the differences in morphology, light‐absorption intensity and band gap of these 2D COFs. The results of photocatalytic H2 evolution measurements indicate that the TpPa−COF−(CH3)2 shows the best activity, while the activity of TpPa−COF−NO2 is relatively low compared to that of other two COFs in the system. Moreover, the separation ability of photogenerated charge was also followed the order of TpPa−COF−(CH3)2>TpPa−COF>TpPa−COF−NO2. The best photocatalytic H2 production performance of TpPa−COF−(CH3)2 in these systems should be mainly attributed to the better electron‐donating ability of −CH3 groups compared to −H or −NO2 group, which result in more efficient charge transferring in the inner of the material. This work demonstrates that reasonably adding electron‐donating group in TpPa−COFs can lead to a better photocatalytic H2 evolution activity, and which is meaningful for further design of efficient COF‐based photocatalysts for H2 evolution.
Photocatalysis: A series ketoenamine‐based COFs of TpPa−COF−X (X=−H, −(CH3)2, and −NO2) exhibit significant difference on the visible light absorbance and efficiency of photocatalytic H2 evolution, which can be attributed to strengthen charge carrier mobilities both in‐plane and in the stacking direction because of the electron‐donating groups.
Primary lung cancer is one of the most common malignant tumors in China. Approximately 60% of lung cancer patients have distant metastasis at the initial diagnosis, so it is necessary to find new ...tumor markers for early diagnosis and individualized treatment. Tumor markers contribute to the early diagnosis of lung cancer and play important roles in early detection and treatment, as well as in precision medicine, efficacy monitoring, and prognosis prediction. The pathological diagnosis of lung cancer in small biopsy specimens determines whether there are tumor cells in the biopsy and tumor type. Because biopsy is traumatic and the compliance of patients with multiple biopsies is poor, liquid biopsy has become a hot research direction. Liquid biopsies are advantageous because they are nontraumatic, easy to obtain, reflect the overall state of the tumor, and allow for real-time monitoring. At present, liquid biopsies mainly include circulating tumor cells, circulating tumor DNA, exosomes, microRNA, circulating RNA, tumor platelets, and tumor endothelial cells. This review introduces the research progress and clinical application prospect of liquid biopsy technology for lung cancer.
The first catalytic asymmetric photoreduction of 1,2‐diketones and α‐keto ketimines under visible light irradiation is reported. A transition‐metal‐free synergistic catalysis platform harnessing ...dicyanopyrazine‐derived chromophore (DPZ) as the photoredox catalyst and a non‐covalent chiral organocatalyst is effective for these transformations. With the flexible use of a chiral Brønsted acid or base in H+ transfer interchange to control the elusive enantioselective protonation, a variety of chiral α‐hydroxy ketones and α‐amino ketones were obtained with high yields and enantioselectivities.
Enantioselective protonation: The first catalytic asymmetric photoreduction of 1,2‐diketones and α‐keto ketimines under visible light irradiation relies on a transition‐metal‐free cooperative catalysis platform that harnesses dicyanopyrazine‐derived chromophore (DPZ) as the photoredox catalyst and a noncovalent chiral organocatalyst. A variety of chiral α‐hydroxy ketones and α‐amino ketones was obtained with high yields and enantioselectivities.
Clear cell renal cell carcinoma (ccRCC) is a heterogeneous disease with features that vary by ethnicity. A systematic characterization of the genomic landscape of Chinese ccRCC is lacking, and ...features of ccRCC associated with tumor thrombus (ccRCC-TT) remain poorly understood. Here, we applied whole-exome sequencing on 110 normal-tumor pairs and 42 normal-tumor-thrombus triples, and transcriptome sequencing on 61 tumor-normal pairs and 30 primary-thrombus pairs from 152 Chinese patients with ccRCC. Our analysis reveals that a mutational signature associated with aristolochic acid (AA) exposure is widespread in Chinese ccRCC. Tumors from patients with ccRCC-TT show a higher mutational burden and genomic instability; in addition, mutations in BAP1 and SETD2 are highly enriched in patients with ccRCC-TT. Moreover, patients with/without TT show distinct molecular characteristics. We reported the integrative genomic sequencing of Chinese ccRCC and identified the features associated with tumor thrombus, which may facilitate ccRCC diagnosis, prognosis and treatment.
Abstract Apricot ( Prunus armeniaca ) is an economically important fruit tree in Beijing, China. However, canker diseases have become one of the main threats to apricot production. In the present ...study, a field survey was conducted in apricot orchards in Beijing and the disease incidence of apricots was surveyed (75.7%). Thirty fungal strains were isolated from branches of apricots. Five species were identified through multilocus phylogenetic (rDNA internal transcribed spacer ITS, large subunit LSU and tef1‐a for Botryosphaeriales; ITS, act , rpb2 , tef1‐a and tub2 for Cytospora ) and morphological analyses, including two new species ( Cytospora huairouensis and C . prunina ) and three known species ( C . leucostoma , Diplodia gallae and Phaeobotryon rhois ). C . leucostoma and P . rhois were identified as the causal agents of canker of apricot by pathogenicity tests conducted on 3‐year‐old plants in the greenhouse. The current study contributed to a theoretical basis for predicting the potential risk of apricot canker in Beijing, China.
In the meiotic prophase, programmed DNA double-strand breaks are repaired by meiotic recombination. Recombination-defective meiocytes are eliminated to preserve genome integrity in gametes. BRCA1 is ...a critical protein in somatic homologous recombination, but studies have suggested that BRCA1 is dispensable for meiotic recombination. Here we show that BRCA1 is essential for meiotic recombination. Interestingly, BRCA1 also has a function in eliminating recombination-defective oocytes.
knockout (KO) rescues the survival of
KO oocytes far more efficiently than removing CHK2, a vital component of the DNA damage checkpoint in oocytes. Mechanistically, BRCA1 activates chromosome asynapsis checkpoint by promoting ATR activity at unsynapsed chromosome axes in
KO oocytes. Moreover,
KO also rescues the survival of asynaptic
KO oocytes. Collectively, our study not only unveils an unappreciated role of chromosome asynapsis in eliminating recombination-defective oocytes but also reveals the dual functions of BRCA1 in safeguarding oocyte genome integrity.
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•For the first time, we designed and constructed a series of Ni(OH)2-modified COFs.•Ni(OH)2 acts as noble-metal free cocatalyst in catalyst system.•Ni(OH)2-X%/TpPa-2 photocatalyst is ...comparable to Pt-containing COF-based catalyts.•Ni(OH)2-X%/TpPa-2 photocatalysts master a high rate of electron transport.•The synergistic effect of TpPa-2 and Ni(OH)2 has been systematic studied.
Covalent-organic frameworks (COFs) have been recognized as an emerging type of photocatalysts for H2 evolution and some of them have shown really outstanding photocatalytic activity with the help of Pt co-catalyst. To avoid the utilization of noble metal in COF-based photocatalysts, for the first time, we designed and constructed a series of nickel hydroxide-modified COF (TpPa-2) composite materials Ni(OH)2-X%/TpPa-2 (X: molar fraction of Ni(OH)2), which show apparently improved photocatalytic H2 evolution activity than that of the parent COF and the activity is comparable to that with Pt (0.3 wt%) co-catalyst. A series of Ni(OH)2-X%/TpPa-2 were prepared by in-situ adding TpPa-2 into the reaction system of Ni(OH)2, and the resulting Ni(OH)2-X%/TpPa-2 exhibit a novel sandwich-like morphology. The results of photocatalytic hydrogen evolution under visible light irradiation show that the optimized photocatalytic H2-evolution rate for Ni(OH)2–2.5%/TpPa-2 is up to 1895.99 μmol·h−1·g−1, which is about 26.3 times higher than that of the parent TpPa-2 and is one of the best performing 2D COF-based photocatalyst for H2 evolution. Further investigation confirm the improved activity should be attributed to the enhanced visible-light absorption of the composite materials contributed from Ni(OH)2 and the synergetic effect of Ni(OH)2 and metallic Ni derived from the in-situ reduction of Ni(OH)2, which promoted the separation of photogenerated electron–holes of the resulting materials. This work not only presents a series of new photocatalysts for efficient H2 evolution but also open an avenue for future design and synthesis of COF-based composite materials acting as a substitute of noble-metal-containing photocatalytic systems.
BRCA1 is critical for DNA double-strand break (DSB) repair by homologous recombination (HR). BRCA1 deficient mice are embryonic lethal. Previous studies have shown that 53BP1 knockout (KO) rescues ...embryonic lethality of BRCA1 hypomorphic mutant mice by restoring HR. Here, we show that 53BP1 KO can partially rescue embryonic lethality of BRCA1 total KO mice, but HR is not restored in BRCA1-53BP1 double knockout (DKO) mice. As a result, BRCA1-53BP1 DKO cells are extremely sensitive to PARP inhibitors (PARPi). In addition to HR deficiency, BRCA1-53BP1 DKO cells have elevated microhomology-mediated end joining (MMEJ) activity and G2/M cell cycle checkpoint defects, causing severe genomic instability in these cells. Interestingly, BRCA1-53BP1 DKO mice rapidly develop thymic lymphoma that is 100% penetrant, which is not observed in any BRCA1 mutant mice rescued by 53BP1 KO. Taken together, our study reveals that 53BP1 KO can partially rescue embryonic lethality caused by complete BRCA1 loss without rescuing HR-related defects. This finding suggests that loss of 53BP1 can support the development of cancers with silenced BRCA1 expression without causing PARPi resistance.
In this work, a comparative study of three frequently employed modification techniques to g-C
3
N
4
(CN) nanosheets for the photocatalytic degradation of metribuzin (MET) under visible-light ...irradiation has been carried out in detail. The modification methods were coupling TiO
2
nanoparticles (TO) as electron acceptors, nano-sized Fe
2
O
3
(FO) to construct a Z-scheme nanocomposite, and phosphate (HP) modification to promote O
2
adsorption. The steady-state and transient-state surface photovoltage spectra and transient photoluminescence (PL) spectra confirmed that all the three modification techniques enhanced the charge separation with prolonged lifetimes and presented degradation activities in the order of TO/CN > FO/CN > HP/CN. The TO/CN nanocomposite showed the highest photocatalytic activity for MET degradation, with a sixfold higher rate than bulk CN. Liquid chromatography–tandem mass spectrometry and radical trapping experiments indicated that the increased activity was related to the synergetic effect of two radicals (·O
2
−
and ·OH) involved in the photocatalytic degradation pathway, which was different from the ·OH radical-dominated pathway of bulk CN. This work reveals the importance of charge separation and the influence of the radical pathway and provides guidance for the design of high-efficiency photocatalysts.
Graphical abstract
The systematic design of functional peptides has technological and therapeutic applications. However, there is a need for pattern-based search engines that help locate desired functional motifs in ...primary sequences regardless of their evolutionary conservation. Existing databases such as The Protein Secondary Structure database (PSS) no longer serves the community, while the Dictionary of Protein Secondary Structure (DSSP) annotates the secondary structures when tertiary structures of proteins are provided. Here, we extract 1.7 million helices from the PDB and compile them into a database (Therapeutic Peptide Design database; TP-DB) that allows queries of compounded patterns to facilitate the identification of sequence motifs of helical structures. We show how TP-DB helps us identify a known purification-tag-specific antibody that can be repurposed into a diagnostic kit for Helicobacter pylori. We also show how the database can be used to design a new antimicrobial peptide that shows better Candida albicans clearance and lower hemolysis than its template homologs. Finally, we demonstrate how TP-DB can suggest point mutations in helical peptide blockers to prevent a targeted tumorigenic protein-protein interaction. TP-DB is made available at http://dyn.life.nthu.edu.tw/design/ .
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