ObjectiveTo systematically compare the differential regulation of the maternal-fetal interface cell lineages and communication networks in the CBA/J×DBA/2 mouse model of recurrent pregnancy loss （RPL） by the two classic therapeutic methods-tonifying the kidney to stabilize the fetus and invigorating the spleen to stabilize the fetus （Shoutai Wan， Juyuan Jian）-of traditional Chinese medicine （TCM） at the single-cell resolution and clarify their modern scientific connotations. MethodsFemale non-pregnant CBA/J mice were caged with male BALB/c （blank group） and DBA/2 （modeling group） mice separately. Pregnant mice in the modeling group were randomly grouped as follows： high/low-dose Shoutai Wan， high/low-dose Juyuan Jian， model （RPL）， and positive control （dydrogesterone）， with 10 mice in each group. Starting from the day after the detection of the vaginal plug， mice were administrated with drugs or an equal volume of normal saline by gavage for 10 consecutive days. After the intervention， the following indicators were measured. ① Macroscopic evaluation： general conditions， uterine wet weight， embryo loss rate， four coagulation parameters ［prothrombin time （PT）， activated partial thromboplastin time （APTT）， fibrinogen （FIB）， and thrombin time （TT）］， and peripheral blood estradiol （E₂） and progesterone （Pg） levels. The decidua with embryos was stained with hematoxylin-eosin （HE） and evaluated by transmission electron microscopy （TEM）. The expression of B-cell lymphoma-2 （Bcl-2）， vascular endothelial growth factor （VEGF）， angiotensin Ⅱ （AngⅡ）， matrix metalloproteinase-2 （MMP-2）， interleukin-6 （IL-6）， leukemia inhibitory factor （LIF）， CXC chemokine ligand 12 （CXCL12）， and microtubule-associated protein 1 light chain 3 homolog （LC3）Ⅰ/Ⅱ was quantified by Western blot. ② Mechanism analysis at the single-cell level： The decidua with embryos from the blank， model， high-dose Shoutai Wan， and high-dose Juyuan Jian groups （6 mice per group， with 3 single-cell samples per group， totaling 24 mice） were analyzed by the BD Rhapsody™ platform， and the whole-cell atlas was drawn by uniform manifold approximation and projection （UMAP） dimensionality reduction clustering combined with the single-cell mouse cell atlas （scMCA）. The differentially expressed genes （DEGs） and cell interaction networks were analyzed via Gene Ontology （GO）， Kyoto Encyclopedia of Genes and Genomes （KEGG）， and CellChat， and the protein-protein interaction （PPI） map of subtype cells was constructed. The CytoTRACE pseudo-temporal analysis was performed to explore the developmental trajectories of core immune cells （natural killer cells， NK cells） from maternal and fetal sources. Results① Pathological and Western blot results indicated that compared with the blank group， the RPL group showed an increase in the embryo loss rate （P<0.01）， down-regulated expression of Bcl-2， LIF， MMP-2， and Vegf in the decidua with embryos （P<0.05）， up-regulated protein levels of CXCL-12， AngⅡ， and IL-6 （P<0.05）， blocked angiogenesis， apoptosis-inflammation imbalance， and coagulation dysfunction. Both prescriptions dose-dependently reduced the abortion rate and restored the angiogenesis-inflammation balance， and Shoutai pill showed superior performance in restoring the E₂ level to the Pg level （P<0.05）. ② Single-cell transcriptome analysis indicated that compared with the blank group， the RPL group showed differences in multiple key cell populations such as decidual cells， trophoblast cells， endothelial cells， erythroblasts， NK cells， and macrophages at the maternal-fetal interface. Immunity and angiogenesis were the key links in RPL. Compared with the RPL group， high-dose Shoutai Wan reversed the changes of NK cells in the embryonic layer （upregulating the mRNA levels of 17 genes and downregulating the mRNA levels of 29 genes） and macrophages （upregulating the mRNA levels of 117 genes and downregulating the mRNA levels of 53 genes） through the regulation of gene expression. High-dose Shoutai pill regulated the immune cells to affect unfolded proteins， cell adhesion， and programmed cell death， thereby promoting decidualization and angiogenesis and modulating embryo-membrane development. High-dose Juyuan Jian regulated the key subgroups of NK cells （up-regulating the mRNA levels of 9 genes and down-regulating the mRNA levels of 17 genes） and macrophages （up-regulating the mRNA levels of 110 genes and down-regulating the mRNA levels of 81 genes）， which affected decidual inflammation and apoptosis and intervened in glycolysis. ③ The pseudo-temporal analysis and communication network indicated that the communication frequency of the RPL group decreased. High-dose Shoutai Wan restored maternal-fetal tolerance through pathways such as NKG2D， CDH5， GDF， and FASLG. High-dose Juyuan Jian enhanced the IL-6/LIFR/JAK/signal transducer and activator of transcription 3 （STAT3） and desmosome/SEMA6/tumor necrosis factor-like weak inducer of apoptosis （TWEAK） signaling to improve endometrial receptivity. The RPL group showed an increased proportion of toxic dNK7， a decreased proportion of reparative dNK4， and blocked embryo fNK1. High-dose Shoutai Wan down-regulated dNK7 and up-regulated dNK4. High-dose Juyuan Jian inhibited the terminal differentiation of dNK7 and up-regulated LILRB1， thus restoring the balance of cytotoxicity and repair. ConclusionBoth the kidney-tonifying and spleen-invigorating methods are effective in treating RPL. NK and macrophages are the key immune cells in the interaction between the embryo and the membrane. The kidney-tonifying method （Shoutai Wan） has an advantage in regulating the phenotypes of unfolded protein， cell adhesion， and programmed cell death， and shows expression characteristics closer to the physiological state in the regulation of NKG2D and CDH5 signals. The spleen-invigorating method （Juyuan Jian） has an advantage in regulating epithelial-mesenchymal transition （EMT）， angiogenesis， and glycolysis and shows higher communication intensity in the IL-6 and LIFR pathways.

Objective: To investigate the environmental contamination of norovirus in nurseries and primary/secondary schools, so as to provide a scientific basis for effective prevention and control measures. Methods: A total of 483 external environmental samples were collected from 34 cluster outbreaks of norovirus gastroenteritis in kindergartens and primary/secondary schools in Linhai City from 2021 to 2024. Pathogen detection was conducted using a rapid nucleic acid extraction kit and realtime fluorescence RT-PCR, and the results were analyzed using the χ2 test or Fishers exact test. Results: Among the collected external environmental samples, the total positive rate of surface contamination was 13.66%. The positive rates in kindergartens and primary/secondary schools were 12.20% and 15.82%, respectively. In kindergartens, the five surfaces with the highest detection rates were desks/chairs (23.33%), toilet stool troughs (20.69%), urinal troughs (12.00%), washbasins/sinks (11.11%), and toilet mops (9.38%). In primary/secondary schools, the top five were toilet stool troughs (38.30%), urinal troughs (23.53%), toilet door handles (13.04%), toilet mops (12.50%), and drinking cups (11.11%). The difference in positive detection rates among different external environments in primary/secondary schools was statistically significant (Fishers exact probability test, P<0.01). The positive detection rate in sanitary toilets was higher than that in classroom environments (χ2=17.38), while the positive detection rate in classroom environments of kindergartens was higher than that in primary/secondary schools (χ2=5.42)(P<0.05). Conclusions Norovirus exhibits a high contamination rate in nurseries and schools, particularly in restroom areas. Strengthening sanitation and disinfection in highrisk environments, and improving hygiene awareness among children and staff, are essential for the effective prevent and control of norovirus.

Guided by the turbidity toxin theory， it is believed that the key pathogenesis of constipation-predominant irritable bowel syndrome is the obstruction of turbidity toxin and the disruption of intestinal function. Treatment is based on the principles of dispelling turbidity toxin and promoting intestinal function. The clinical patterns can be divided into three types， turbidity toxin heat accumulation pattern， turbidity toxin combined with liver depression and qi stagnation pattern， and turbidity toxin combined with qi and yin deficiency pattern. The treatment can respectively use self-prescribed Tongfu Jiangzhuo Formula （通腑降浊方） to clear heat and unblock the bowels， direct the turbid downward and resolve toxins； use self-prescribed Shugan Jiangzhuo Formula （疏肝降浊方） to soothe the liver and move qi， direct the turbid downward and resolve toxins； use self-prescribed Mazhi Jiangzhuo Formula （麻枳降浊方） to boost qi and nourish yin， moisten the intestines to remove turbidity and resolve toxins.

BACKGROUND:Ursolic acid can promote the directed differentiation of bone marrow mesenchymal stem cells into osteoblasts.However,there are few reports on whether ursolic acid has osteogenic effect on human periodontal ligament stem cells. OBJECTIVE:To investigate the effect of ursolic acid on proliferation and osteogenic differentiation of human periodontal ligament stem cells. METHODS:The human periodontal ligament stem cells were isolated and cultured.Passage 3 cells were selected and treated with ordinary medium containing different concentrations(0,1,2,4,6,8 μmol/L)of ursolic acid.After intervention for 1,3,5,7 days,the cell proliferation was detected by CCK-8 assay and the appropriate intervention concentration was screened.Passage 3 human periodontal ligament stem cells were treated with osteogenic induction solution containing 0,1,2,4 μmol/L ursolic acid,respectively.After 7 days of intervention,the mRNA expressions of alkaline phosphatase,Runx2,and osteocalcin were detected by qRT-PCR.After 14 days of intervention,the formation of mineralized nodules was observed by alizarin red staining.Passage 3 human periodontal ligament stem cells were taken and the control group was added with osteogenic induction solution;the ursolic acid group and the antagonist group were added with osteogenic induction solution containing ursolic acid(2 μmol/L)and the bone morphogenetic protein signaling pathway antagonist Noggin,respectively.The ursolic acid+antagonist group was added with osteogenic induction solution containing ursolic acid(2 μmol/L)and Noggin,the inhibitor of bone morphogenetic protein signaling pathway,and cultured for 7 days.qRT-PCR and western blot assay were used to detect the mRNA and protein expressions of bone morphogenetic protein 2,Smad1,osteopontin,and Runx2. RESULTS AND CONCLUSION:(1)1,2,4 μmol/L ursolic acid could promote the proliferation of human periodontal ligament stem cells.6,8 μmol/L ursolic acid could inhibit the proliferation of human periodontal ligament stem cells,and 1,2,4 μmol/L ursolic acid was selected to intervene in subsequent experiments.(2)Compared with 0 μmol/L,1,2,4 μmol/L ursolic acid could promote the expression of alkaline phosphatase,Runx2,and osteocalcin mRNA and the formation of mineralized nodules(P<0.05),and the effect of 2 μmol/L ursolic acid was the most significant.(3)Compared with the control group,the mRNA and protein expressions of bone morphogenetic protein 2,Smad1,osteopontin,and Runx2 in the ursolic acid group were increased(P<0.05),while mRNA and protein expressions of the above indexes were decreased in the antagonist group(P<0.05).Compared with the ursolic acid group,mRNA and protein expressions of above indexes were decreased in ursolic acid+antagonist group(P<0.05).(4)The results indicate that ursolic acid promotes osteogenic differentiation of human periodontal ligament stem cells through bone morphogenetic protein signaling pathway.

OBJECTIVE:High-intensity interval training(HIIT)and moderate-intensity continuous training(MICT)can improve the quality of life of patients with clinical chronic diseases,but their application effects and regulatory factors in adults with insufficient physical activity are still unclear.This study aimed to explore the application effects and regulatory factors of HIIT and MICT on the quality of life of adults with insufficient physical activity. METHODS:A systematic literature search was conducted in databases including Web of Science Core Collection,Medline(EBSCO Host),PubMed,and Cochrane Library.The search time limit was from the establishment of each database to September 2023.The types of included literature were randomized controlled trials,and the research subjects were physically inactive adults.RevMan 5.4 software and the GRADE evidence evaluation framework were used to assess the quality of the included literature.Main effects pooling of random effects models was performed using R Studio(version 4.2.0).Subgroup analyses,regression analyses,and sensitivity analyzes were used to explore the sources of study heterogeneity and moderators. RESULTS:(1)Thirty-two randomized controlled trials of moderate to high quality were included,involving 2 083 physically inactive adults(HIIT group n=474;MICT group n=708;control group n=901).(2)Compared with the non-training control group,HIIT[Hedges'g=0.61;95%confidence interval(CI):0.40-0.83;I2=45%]and MICT(Hedges'g=0.66;95%CI:0.25-1.08;I2=89%)significantly improved the quality of life.Direct comparison studies of HIIT and MICT found no significant differences in the quality of life(Hedges'g=-0.01;95%CI:-0.23-0.21;I2=0%).(3)Subgroup analysis showed that HIIT and MICT were more effective in improving the physical components of the quality of life(HIIT:Hedges'g=0.82 vs.0.75;MICT:Hedges'g=0.74 vs.0.55),while cycling had a better trend in improving overall quality of life(HIIT:Hedges'g=0.74 vs.0.36;MICT:Hedges'g=1.08 vs.0.52).(4)Additionally,regression analysis did not identify any significant moderators(P>0.05 for all factors).(5)None of the above meta-analyses found publication bias(Egger test P>0.05). CONCLUSION:(1)Moderate to high level evidence shows that both HIIT and MICT can improve the quality of life of adults with insufficient physical activity,and the intervention effects between the two are similar.Therefore,when choosing between these two options,it is necessary to comprehensively consider factors such as time economy,scheduling flexibility,and application feasibility to formulate a personalized exercise plan.(2)This study recommends that when applying HIIT,a low-volume protocol(for example,5 groups each time,1 minute each),3 times/week,and ride at 80%-95%of the maximum heart rate is used to achieve the theoretical best improvement effect.(3)Although MICT improves the quality of life,there is insufficient evidence that increasing exercise duration brings additional benefits.Therefore,this study recommends that when MICT is conducted,it should be carried out more than three times a week,with each training duration controlled between 25 and 60 minutes,and cycling at 50%-75%of the maximum heart rate,in order to achieve the theoretically expected best improvement effect.

In recent years, cancer treatment methods and means are becoming more and more diversified, and single treatment methods often have limited efficacy, while the synergistic effect of immunity combined with chemotherapy can inhibit tumor growth more effectively. Based on this, we constructed a sodium alginate hydrogel composite system loaded with chemotherapeutic agents and tumor vaccines (named SA-DOX-NA) with a view to the combined use of chemotherapeutic agents and tumor vaccines. Firstly, the tumor vaccine (named NA) degradable under acidic conditions was constructed by in situ polymerization using chicken ovalbumin (OVA), acrylamide (AAM) and 2-(dimethylamino) ethyl methacrylate (DMAEMA) monomer. Then a hydrogel composite system SA-DOX-NA co-loaded with chemotherapeutic drug doxorubicin (DOX) and NA was prepared using sodium alginate as a matrix. The results showed that SA-DOX-NA had good in situ gel-forming ability and formed a mesh structure that could realize the co-loading of DOX and NA as well as the slow drug release. The electron microscopy results showed that SA-DOX-NA had good in situ gel-forming ability with good internal connectivity, and the three-dimensional mesh structure could realize the co-loading of DOX and NA as well as the slow drug release. The antitumor and immunomodulatory results showed that SA-DOX-NA both effectively inhibited the growth of tumor cells and efficiently promoted the proliferation and activation of DC2.4 dendritic cells without additional adjuvant. In summary, SA-DOX-NA exerts the dual efficacy of chemotherapy and immunotherapy for tumor treatment, and has a good application prospect in local tumor treatment.

ObjectiveTo investigate the mechanism of Huazhuo Jiedu prescription in treating ulcerative colitis （UC） by regulating mitophagy. MethodsThe genes related to mitophagy and UC were retrieved from GeneCards， and then the common genes of mitophagy and UC were analyzed by metascape to identify the genes related to mitophagy in UC. Animal experiments were carried out to decipher the mechanism by which Huazhuo Jiedu prescription treated UC by regulating mitophagy. Sixty C57BL/6 male mice were randomized into normal， model， high-， medium-， and low-dose （50， 25， 12.5 g·kg^-1， respectively） Huazhuo Jiedu prescription， and mesalazine （0.52 g·kg^-1·d^-1） groups， with 10 mice in each group. After successful modeling by the dextran sulfate sodium-free drinking method， the colonic mucosal damage was observed by hematoxylin-eosin staining， and the ultracellular structure of colon mucosa was observed by transmission electron microscopy. The expression levels of mitophagy-related proteins PTEN-induced putative kinase 1 （PINK1） and Parkin protein were determined by Western blot. The expression of prohibitin 2 （PHB2）， ubiquitin-specific protease 15 （USP15）， ubiquitin-specific protease 30 （USP30） in the colon tissue was detected by immunofluorescence （IF）. ResultsAll the drug intervention groups showed ameliorated pathological manifestations of the colonic mucosa and improved mitochondrial structures in UC mice. Compared with the normal group， the model group demonstrated up-regulated protein levels of PINK1 and Parkin （P<0.05）， enhanced average fluorescence intensity of PHB2 （P<0.05）， and weakened average fluorescence intensity of USP15 and USP30 （P<0.05）. Compared with the model group， the mesalazine group and the high- and medium-dose Huazhuo Jiedu prescription groups showcased down-regulated protein levels of PINK1 and Parkin （P<0.05）， decreased average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. The low-dose Huazhuo Jiedu prescription group showed down-regulated protein levels of PINK1 and Parkin （P<0.05）， weakened average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. ConclusionHuazhuo Jiedu prescription can attenuate the intestinal mucosal injury and improve the mitochondrial cell ultrastructure in UC mice by regulating the expression of PINK1-Parkin pathway and inhibiting excessive mitophagy.

ObjectiveTo investigate the mechanism of Huazhuo Jiedu prescription in treating ulcerative colitis （UC） by regulating mitophagy. MethodsThe genes related to mitophagy and UC were retrieved from GeneCards， and then the common genes of mitophagy and UC were analyzed by metascape to identify the genes related to mitophagy in UC. Animal experiments were carried out to decipher the mechanism by which Huazhuo Jiedu prescription treated UC by regulating mitophagy. Sixty C57BL/6 male mice were randomized into normal， model， high-， medium-， and low-dose （50， 25， 12.5 g·kg^-1， respectively） Huazhuo Jiedu prescription， and mesalazine （0.52 g·kg^-1·d^-1） groups， with 10 mice in each group. After successful modeling by the dextran sulfate sodium-free drinking method， the colonic mucosal damage was observed by hematoxylin-eosin staining， and the ultracellular structure of colon mucosa was observed by transmission electron microscopy. The expression levels of mitophagy-related proteins PTEN-induced putative kinase 1 （PINK1） and Parkin protein were determined by Western blot. The expression of prohibitin 2 （PHB2）， ubiquitin-specific protease 15 （USP15）， ubiquitin-specific protease 30 （USP30） in the colon tissue was detected by immunofluorescence （IF）. ResultsAll the drug intervention groups showed ameliorated pathological manifestations of the colonic mucosa and improved mitochondrial structures in UC mice. Compared with the normal group， the model group demonstrated up-regulated protein levels of PINK1 and Parkin （P<0.05）， enhanced average fluorescence intensity of PHB2 （P<0.05）， and weakened average fluorescence intensity of USP15 and USP30 （P<0.05）. Compared with the model group， the mesalazine group and the high- and medium-dose Huazhuo Jiedu prescription groups showcased down-regulated protein levels of PINK1 and Parkin （P<0.05）， decreased average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. The low-dose Huazhuo Jiedu prescription group showed down-regulated protein levels of PINK1 and Parkin （P<0.05）， weakened average fluorescence intensity of PHB2 （P<0.05）， and enhanced average fluorescence intensity of USP15 and USP30 （P<0.05）. ConclusionHuazhuo Jiedu prescription can attenuate the intestinal mucosal injury and improve the mitochondrial cell ultrastructure in UC mice by regulating the expression of PINK1-Parkin pathway and inhibiting excessive mitophagy.

OBJECTIVE To estimate the cost-effectiveness of penpulimab combined with chemotherapy versus chemotherapy alone in first-line treatment of advanced squamous non-small-cell lung cancer （sq-NSCLC）. METHODS From the perspective of Chinese health system， cost-utility analysis was used to evaluate the cost-effectiveness of penpulimab combined with chemotherapy （paclitaxel + carboplatin） versus chemotherapy （paclitaxel + carboplatin） in first-line treatment of sq-NSCLC. A three-health states Markov model was constructed with R packages， and clinical data used in the model were derived from the AK105-302 clinical trial. Costs and utilities were collected from the open-access database and published literature. The quality-adjusted life-years （QALY） was used as the utility index， and the willingness-to-pay （WTP） threshold was set at three times China’s per capita GDP in 2024， equivalent to 287 247 yuan/QALY. The cost-effectiveness of the schemes was evaluated by comparing the incremental cost- utility ratios （ICER） of the two schemes with the WTP threshold. One-way sensitivity analysis and probabilistic sensitivity analysis （PSA） were used to verify the stability of the basic analysis results. RESULTS Compared with chemotherapy， penpulimab combined with chemotherapy increased 0.73 QALY with an incremental cost of 150 681.93 yuan， and the ICER was 206 413.60 yuan/QALY. One-way sensitivity analysis showed that the utility of progression-free survival was the most sensitive factor on ICERs. At the WTP threshold of 3 times China’s per capita GDP， the economic probability of this scheme was 98.80%. At the WTP threshold of 1 times China’s per capita GDP， the probability of ICER being cost-effective was less than 0.01%. CONCLUSIONS For patients with advanced sq-NSCLC， penpulimab combined with chemotherapy is a cost-effective first-line treatment option when WTP threshold is 3 times China’s per capita GDP.

ObjectiveTo explore the sequential effects of hypoxic exercising on miR-27/PPARγ and lipid metabolism target gene and protein expression levels in the obesity rats’ liver. Methods13-week-old male diet-induced obesity rats were randomly divided into three groups (n＝10): normal oxygen concentration quiet group (N), hypoxia quiet group (H), hypoxic exercise group (HE). Exercise training on the horizontal animal treadmill for 1 h/d, 5 d/week for a total of 4 week, and the intensity of horizontal treadmill training was 20 m/min (hypoxic concentration was 13.6%). Comparison of the weights of perirenal fat and epididymal fat in rats across different groups and calculation of Lee’s index based on body weight and body length of rats in each group were done. And the serum concentrations of total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) levels were detected. RT-PCR and Western Blot were used to detect the levels of miR-27, PPARγ, CYP7A1 and CD36. ResultsHypoxic exercise decreased the expression levels of miR-27 in the obese rats’ liver, however, the expression level of PPARγ was gradually increased. The expression levels of miR-27 in HE group were significantly lower than N group (P<0.05). The expression levels of PPARγ mRNA in N group were significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The protein expression of PPARγ protein in N group was significantly lower than that other groups (P<0.01). The expression of lipid metabolism-related genes and proteins increased in the obese rats’ liver. The expression of CYP7A1 mRNA in N group was significantly lower than H group (P<0.05), especially lower than HE group (P<0.01). The expression of CYP7A1 protein in the obese rats’ liver in N group was extremely lower than H group and HE group (P<0.01). The protein expression of CD36 in N group was significantly lower than that in HE group (P<0.05). Hypoxia exercise improved the related physiological and biochemical indexes of lipid metabolism disorder. The perirenal fat weight of obese rats in HE group was extremely lower than N group and H group (P<0.01), and the perirenal fat weight in N group was significantly higher than H group (P<0.05). The epididymal fat weight in N group was significantly higher than H group (P<0.05), and extremely higher than HE group (P<0.01). The Lee’s index in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TC in obese rats in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of TG in HE group was extremely lower than N group and H group (P<0.01). The serum concentration of LDL-C in N group was extremely higher than HE group (P<0.01). The serum concentration of HDL-C in N group was extremely lower than H group (P<0.01). ConclusionHypoxia and hypoxia exercise may negatively regulate the levels of PPARγ by inhibiting miR-27 in the obese rats’ liver, thereby affecting the expression of downstream target genes CYP7A1 and CD36, and promoting cholesterol, fatty acid oxidation and HDL-C transport in the liver, and ultimately the lipid levels in obese rats were improved. The effect of hypoxia exercise on improving blood lipid is better than simple hypoxia intervention.