This study unravels the characteristics, mechanisms, and predictability of four consecutive record‐breaking heatwaves hitting North China in June and July 2023. The first three heatwaves primarily ...influenced the northern part of North China and were accompanied by consistent anticyclonic anomalies in the upper troposphere. The anomalous anticyclone was caused by the British–Baikal corridor teleconnection along the polar front jet, particularly during the second heatwave. In contrast, the fourth heatwave was induced by a distinct low‐pressure system, attributed to the Silk Road pattern along the subtropical jet. The presence of this low‐pressure system and its interaction with atmospheric rivers and local topography led to the foehn wind, further contributing to the rise in surface temperatures. Sub‐seasonal to seasonal models can effectively predict the occurrence of all heatwaves 2–5 days in advance despite underestimating the intensity. However, models exhibit limitations in providing reliable predictions when the lead time exceeds 2 weeks.
Plain Language Summary
In the summer of 2023, North China experienced four consecutive extreme high‐temperature events, which are called heatwaves. This study investigates the main factors that cause the four events and shows how well the operational numerical models can predict the heatwaves. The first three heatwaves shared similar circulation, with high‐pressure systems controlling North China. This local circulation anomaly was related to an upstream quasi‐stationary wave train along the polar front jet. The fourth heatwave was associated with a low‐pressure system over North China and an upstream quasi‐stationary wave train along the subtropical jet. Moreover, predictions from operational models demonstrate their capability to forecast the occurrence of high temperatures 2–5 days ahead, with an underestimation in the intensity. However, models are not reliable when it comes to predicting heatwaves 2 weeks in advance.
Key Points
North China witnessed record‐breaking heatwaves in June and July 2023, consisting of four sequential synoptic‐scale events
The first three and the last heatwaves are controlled by distinct local circulations induced by atmospheric wave trains across Eurasia
S2S models capture the heatwave occurrences 2–5 days in advance, but predictive skill notably diminishes beyond 2 weeks
•CO2 dissolution and exsolution behavior was investigated in visual cell.•A MATLAB-controlled reservoir simulator with real-time optimization was developed.•Diffusion coefficients of CO2 into heavy ...oil phase were achieved.•Kinetic reaction rate frequency factors of CO2 exsolution were achieved.
A novel methodology utilizing high-pressure Hele-Shaw-like visual cell has been developed to study solvent dissolution and exsolution behavior of a CO2-heavy oil system. The experimental setup overcomes the visualization shortcomings of traditional apparatuses such as a hardly-visual cylindrical PVT cell, or non-visual transfer cylinders. Experimentally, a heavy oil sample (viscosity at 1500cP at de-gassed state) was used to conduct solvent dissolution and exsolution tests. CO2 diffusion tests have been conducted by pressure decay method. At the end of each diffusion stage, pressure depletion tests were subsequently conducted on the CO2-heavy oil system to study foamy oil stability under different pressure depletion schemes. The effect of various factors on the foamy oil volumetric behavior have been investigated, including the effect of initial solution GOR, continuous pressure depletion rate, immediate pressure drawdown level and solvent-heavy oil contact time. A MATLAB-controlled reservoir simulator was developed for numerical validation. For solvent dissolution tests, CO2 diffusion coefficient in oil (intra-phase mass transfer) was optimized and achieved by history matching the pressure decay curves. Results showed that, diffusion coefficients increased from 6.198 × 10−9 to 25.333 × 10−9m2/s when pressure increased from 1555 to 3320 kPa. Solvent exsolution behavior was simulated through defining multiple kinetic reactions. Kinetic reaction rate frequency factors (RRFs), which indicated the rate of multi-component inter-phase mass transfer, were achieved by history matching foamy oil volume under multiple operational schemes. Comparing RRFs, foamy oil stability was found to be increasing under higher initial GOR, pressure depletion rate and pressure drawdown as well as for longer solvent-heavy oil contact time.
Learning burnout negatively influences students' learning and well-being. Sleep quality is directly related to students' health and learning outcomes. Research indicates that sleep quality and coping ...style may be associated with learning burnout. However, the interrelationship among learning burnout, sleep quality, and coping style has not yet been fully studied. This study aimed to explore the relationship between sleep quality and learning burnout and examine whether coping mediates this relationship in Chinese university students. A total of 228 undergraduate students were recruited to participate in this research. The Simplified Coping Style Questionnaire (SCSQ), Learning Burnout Questionnaire (LBQ), and Pittsburgh Sleep Quality Index-Chinese (PSQI-C) were employed to collect data. The results showed the following: (1) poor sleep quality had a positive association with learning burnout, and (2) active coping style mediated the effects of poor sleep quality on learning burnout and the dimensions of learning burnout (depression and low sense of achievement). The findings of the current study contribute to knowledge of learning burnout and provide theoretical evidence for further educational interventions.
Radiotherapy is inevitably intertwined with various side effects impairing the quality of life of cancer patients. Here, we report the possibility that alterations of the oral microbiota influence ...the therapeutic efficacy and prognosis of radiotherapy for primary rectal cancer and colorectal cancer (CRC) liver metastases that pathologically disrupt gastrointestinal integrity and function. 16S rRNA sequencing shows that oral microbiota alterations change the gut bacterial composition within tumors but not in adjacent peritumor tissues in CRC mouse models. Specifically, buccal Fusobacterium nucleatum migrates to the CRC locus and impairs the therapeutic efficacy and prognosis of radiotherapy. Administration of a specific antibiotic, metronidazole, abrogates the adverse effects of oral microbiome fluctuation on radiotherapy for CRC. The oral microbiota were also associated with radiation-induced intestinal injury via intestinal microbes. Our findings demonstrate that the oral microbiome in synergy with its intestinal counterparts impinges on the efficacy and prognosis of radiotherapy for CRC.
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•Colorectal cancer (CRC) progression is affected by oral microbiota•Oral microbiota alterations affect efficacy of radiotherapy and prognosis in CRC•Changes in oral microbiome tune bacterial pattern at CRC site but not peritumor•Oral F. nucleatum migrates to CRC sites, impairing radiotherapy
Dong et al. report that oral microorganisms such as Fusobacterium nucleatum can colonize colorectal cancer (CRC) sites and impair the therapeutic efficacy of radiotherapy and prognosis for primary rectal cancer and CRC liver metastases. Metronidazole, a Fusobacterium-killing antibiotic, is a potential radiosensitizer for the treatment of gastrointestinal tumors.
Radiation therapy toward malignancies is often ineffective owing to radioresistance of cancer cells. On the basis of anti-tumor properties of cordycepin, we examined the effects of cordycepin on ...sensitizing breast cancer cells toward radiotherapy. Cordycepin administration promoted G2/M arrest and apoptosis of MCF-7 and MDA-MB-231 cells resulting in restraining the proliferation of the cells in vitro and in vivo following irradiation. Mechanistic investigations showed that the breast cancer cells cultured with cordycepin harbored higher levels of intracellular reactive oxygen species (ROS) and incremental numbers of γ-H2AX foci after irradiation exposure. Importantly, cordycepin treatment down-regulated the expression levels of Nuclear factor erythroid 2-related factor (Nrf2) and a series of downstream genes, such as heme oxygenase-1 (HO-1), to enhance ROS in breast cancer cells exposed to irradiation. Together, our observations demonstrate that cordycepin treatment sensitizes breast carcinoma cells toward irradiation via Nrf2/HO-1/ROS axis. Thus, our findings provide novel insights into the function and the underlying mechanism of cordycepin in radiotherapy, and suggest that cordycepin might be employed as a radiosensitizer during radiotherapy toward breast cancer in a pre-clinical setting.
•Cordycepin sensitizes breast carcinoma cells toward irradiation covering TNBC.•Cordycepin administration induces DNA damage following irradiation.•Cordycepin hijacks Nrf2/HO-1/ROS axis to sensitize breast cancer cells toward IR.•Clinically, cordycepin might be employed as a radiosensitizer for breast cancer.
Radiation-induced cardiopulmonary injuries are the most common and intractable side effects that are entwined with radiotherapy for thorax cancers. However, the therapeutic options for such ...complications have yielded disappointing results in clinical applications. Here, we reported that gut microbiota-derived l-Histidine and its secondary metabolite imidazole propionate (ImP) fought against radiation-induced cardiopulmonary injury in an entiric flora-dependent manner in mouse models. Local chest irradiation decreased the level of l-Histidine in fecal pellets, which was increased following fecal microbiota transplantation. l-Histidine replenishment via an oral route retarded the pathological process of lung and heart tissues and improved lung respiratory and heart systolic function following radiation exposure. l-Histidine preserved the gut bacterial taxonomic proportions shifted by total chest irradiation but failed to perform radioprotection in gut microbiota-deleted mice. ImP, the downstream metabolite of l-Histidine, accumulated in peripheral blood and lung tissues following l-Histidine replenishment and protected against radiation-induced lung and heart toxicity. Orally gavaged ImP could not enter into the circulatory system in mice through an antibiotic cocktail treatment. Importantly, ImP inhibited pyroptosis to nudge lung cell proliferation after radiation challenge. Together, our findings pave a novel method of protection against cardiopulmonary complications intertwined with radiotherapy in pre-clinical settings and underpin the idea that gut microbiota-produced l-Histidine and ImP are promising radioprotective agents.
Background
Breast cancer (BRCA) is the leading cause of cancer‐related death in women worldwide. Pre‐ and postoperative radiotherapy play a pivotal role in BRCA treatment but its efficacy remains ...limited and plagued by the emergence of radiation resistance, which aggravates patient prognosis. The long noncoding RNA (lncRNA)‐implicated mechanisms underlying radiation resistance are rarely reported. The aim of this study was to determine whether lncRNA HOX transcript antisense RNA (HOTAIR) modulated the radiosensitivity of breast cancer through HSPA1A.
Methods
A Gammacell 40 Exactor was used for irradiation treatment. Bioinformatic tools and luciferase reporter assay were adopted to explore gene expression profile and demonstrate the interactions between lncRNA, miRNA and target mRNA 3′‐untranslated region (3′‐UTR). The expression levels of certain genes were determined by real‐time PCR and western‐blot analyses. in vitro and in vivo functional assays were conducted by cell viability and tumorigenicity assays.
Results
The levels of oncogenic lncRNA HOTAIR were positively correlated with the malignancy of BRCA but reversely correlated with the radiosensitivity of breast cancer cells. Moreover, the expression levels of HOTAIR were positively associated with those of heat shock protein family A (Hsp70) member 1A (HSPA1A) in clinical BRCA tissues and HOTAIR upregulated HSPA1A at the mRNA and protein levels in irradiated BRCA cells. Mechanistically, miR‐449b‐5p restrained HSPA1A expression through targeting the 3′‐UTR of HSPA1A mRNA, whereas HOTAIR acted as a competing sponge to sequester miR‐449b‐5p and thereby relieved the miR‐449b‐5p‐mediated HSPA1A repression. Functionally, HOTAIR conferred decreased radiosensitivity on BRCA cells, while miR‐449b‐5p overexpression or HSPA1A knockdown abrogated the HOTAIR‐enhanced BRCA growth under the irradiation exposure both in vitro and in vivo.
Conclusions
LncRNA HOTAIR facilitates the expression of HSPA1A by sequestering miR‐449b‐5p post‐transcriptionally and thereby endows BRCA with radiation resistance.
Key points
Therapeutically, HOTAIR and HSPA1A may be employed as potential targets for BRCA radiotherapy. Our findings shed new light into the mechanism by which lncRNAs modulate the radiosensitivity of tumors.
The radioresistant signature of colorectal cancer (CRC) hampers the clinical utility of radiotherapy. Here, we find that fecal microbiota transplantation (FMT) potentiates the tumoricidal effects of ...radiation and degrades the intertwined adverse events in azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CRC mice. FMT cumulates Roseburia intestinalis (R. intestinalis) in the gastrointestinal tract. Oral gavage of R. intestinalis assembles at the CRC site and synthetizes butyrate, sensitizing CRC to radiation and alleviating intestinal toxicity in primary and CRC hepatic metastasis mouse models. R. intestinalis-derived butyrate activates OR51E1, a G-protein-coupled receptor overexpressing in patients with rectal cancer, facilitating radiogenic autophagy in CRC cells. OR51E1 shows a positive correlation with RALB in clinical rectal cancer tissues and CRC mouse model. Blockage of OR51E1/RALB signaling restrains butyrate-elicited autophagy in irradiated CRC cells. Our findings highlight that the gut commensal bacteria R. intestinalis motivates radiation-induced autophagy to accelerate CRC cell death through the butyrate/OR51E1/RALB axis and provide a promising radiosensitizer for CRC in a pre-clinical setting.
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•FMT improves the efficacy of radiotherapy to CRC without impacting the tumorigenesis•Gut commensal R. intestinalis sensitizes CRC to radiotherapy through producing butyrate•Butyrate facilitates autophagy via OR51E1/RALB axis to induce CRC cell death
Dong et al. identify the radiosensitization of FMT toward CRC. They further screen out the key gut commensal bacteria strain R. intestinalis, which elicits radiogenic autophagy through butyrate/OR51E1/RALB signaling, to improve the therapeutic efficacy of radiotherapy for primary rectal cancer and CRC liver metastases.
The Negative Problem Orientation Questionnaire (NPOQ) is a widely used tool for assessing negative problem orientation (NPO). However, its construct and measurement invariance has not been adequately ...tested in adolescents. The present study explored the possible construct of the NPOQ and its measurement invariance in a sample of 754 Chinese adolescents (51.6% girls, all 12-18 years old). The results supported a bifactor model of the NPOQ that consists of a general factor NPO and three domain-specific factors including perceived threat, self-inefficacy, and negative outcome expectancy. A multiple-group CFA indicated that the bifactor model showed strict invariance across gender and age. The general and domain factors showed unique variance in indexes of worry, depression, anxiety, and stress, which supported well incremental validity of them. This study confirms for a bifactor conceptualization of the NPOQ and its measurement invariance across gender and age in Chinese adolescents. Additionally, it is recommended that the total score should be used to assess NPO in Chinese adolescents.
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