Synthesis and in vitro antifungal activity of new Michael-type amino derivatives of xanthatin, a natural sesquiterpene lactone from Xanthium strumarium L.

Structural optimization using plant secondary metabolites as templates is one of the important approach to discover pesticide molecules with novel skeletons. Xanthatin, a natural sesquiterpene lactone isolated from the Xanthium plants (Family: Compositae), exhibits important biological properties. In this work, a series of Michael-type amino derivatives were prepared from xanthatin and their structures were characterized by 1H NMR, 13C NMR and HR-MS, and their antifungal activities against several phytopathogenic fungi were evaluated according to the spore germination method and mycelium growth rate method in vitro. The results illustrated that compounds 2g (IC50 = 78.91 µg/mL) and 2o (IC50 = 64.51 µg/mL) exhibited more promising inhibition activity against spores of F. solani than precursor xanthatin, compounds 2g, 2l, and 2r exhibited remarkable antifungal effect on C. mandshurica with the average inhibition rates (AIRs) >90%, whereas the AIR of xanthatin was only 59.34%. Meanwhile, the preliminary structure-activity relationships suggested that the amino containing 2-methoxyethyl or 4-chlorophenylmethyl group appended in the C-13 position of xanthatin could yield potential compounds against fungal spores, and the exocyclic double bond of xanthatin is essential to maintain its mycelial growth inhibitory activity. Therefore, the aforementioned findings indicate that partial xanthatin amino-derivatives could be considered for further exploration as the potential lead structures toward development of the new environmentally friendly fungicidal candidates for sustainable crop protection.

Semisynthesis and insecticidal bioactivities of benzoxazole and benzoxazolone derivatives of honokiol, a naturally occurring neolignan derived from Magnolia officinalis.

Honokiol, a natural bioactive neolignan isolated from the bark and leaf of Magnolia officinalis and Magnolia obovata, exhibits many important biological properties. In continuation of our interest in discovery of the agrochemicals derived from the natural sources, thirty-seven new 8/8'-alkylthiol-benzoxazole and N-alkyl/sulfonyl-benzoxazolone derivatives of honokiol were prepared and their insecticidal activities were evaluated against the larvae of Mythimna separata Walker and Plutella xylostella Linnaeus. The results showed that eleven derivatives exhibited potent insecticidal activity against M. separata when compared with the positive control. Particularly, compound 5h displayed the most promising insecticidal activity against M. separata with the final mortality rate (FMR) of 58.6%. Meanwhile, compounds 7n (FMR = 65.3%), 7p (FMR = 61.5%), and 8c (FMR = 65.3%) demonstrated a greater insecticidal activity against P. xylostella than toosendanin, a well-known botanical insecticide. Additionally, the preliminary structure-activity relationships (SARs) were also discussed. This study indicates that these honokiol derivatives could be used as leads for the further derivation and development of the potential pesticide candidates for crop protection.

Analysis of antibiotic treatment of children in a Shanghai tertiary hospital based on point prevalence surveys.

BACKGROUND: Misuse and overuse of antibiotics by physicians in the treatment of children is common in China. This study aimed to reveal the overall use of antibiotics to treat children hospitalized in four types of pediatric wards. METHODS: Seven independent point prevalence surveys (PPSs) were conducted in Shanghai Children's Hospital of Shanghai Jiao Tong University over the period 2012 to 2018. Pediatric ward types were defined general pediatric medical, pediatric surgical, pediatric intensive care units (PICU), and neonatal. RESULTS: A total of 3975 pediatric patients were included in the study, of which 63.9% received at least one dose antibiotic. The top five classes of antibiotics administered were cephalosporins (43.8%, n = 1743), penicillins (13.2%, n = 526), carbapenems (8.7%, n = 347), nitroimidazoles (7.1%, n = 281) and macrolides (6.5%, n = 257). The five most commonly used generic antibiotics were cefuroxime (14.9%, n = 594), ceftriaxone (9.7%, n = 387), cefotaxime (9.0%, n = 358), meropenem (8.1%, n = 320) and ampicillin/sulbactam (6.0%, n = 239). Meropenem was among top five antibiotics prescribed in the general pediatric, PICU and neonatal wards and sixth in the pediatric surgical wards. Of all children on antibiotics, 23.4% received prophylactic treatment, and prophylaxis accounted for 68.1% of indications for treatment in the pediatric surgical wards. CONCLUSIONS: Given that over-treatment with third-generation cephalosporins and carbapenems has been associated with treatment-resistant infections, the prescription of these drugs should be strictly controlled and monitored, and measures should be taken to improve the management of surgical prophylaxis in hospitalized children in China.

Natural product-based semisynthesis and biological evaluation of thiol/amino-Michael adducts of xanthatin derived from Xanthium strumarium as potential pesticidal agents.

Xanthatin, a natural sesquiterpene lactone, occurs as one of the major constituents of Xanthium plants (Compositae) and exhibits many important biological properties. To discover natural products-based pesticides, forty-nine Michael-type thiol/amino adducts of xanthatin were synthesized and characterized, while their pesticidal activities were investigated. Among them, compounds 2c, 2h, 2i, and 2t exhibited more potent antifungal activity against Botrytis cinerea (IC50 = 0.96, 0.38, 6.33, and 7.21 µg/mL, respectively) than xanthatin and the two commercial fungicides. Compounds 2t and 2u displayed broad-spectrum and excellent antifungal effects against all tested phytopathogenic fungi, while their IC50 values ranged from 7.21 to 75.88 µg/mL. Compounds 2a, 2f, 2l, 2m, 2v, 7c, 7e, 7h, 7i, and 7j showed moderate larvicidal activity against Plutella xylostella Linnaeus. Furthermore, compounds 2b, 7g, and 7h demonstrated significant ovicidal activity against P. xylostella with the LC50 values of 14.04, 10.00, and 11.95 mg/L, respectively. These findings suggest that thiol/amino appended in the C-13 position of xanthatin may improve antifungal and ovicidal activities for the derivatives. It was also noticed that the exocyclic double bond of xanthatin is crucial for its larvicidal activity. This work also provides some important hints for further design, synthesis, and structural modification of the xanthanolides sesquiterpene lactones toward development of the new environmentally friendly pesticides for sustainable agricultural production.

Exosome-Mediated miR-155 Transfer from Smooth Muscle Cells to Endothelial Cells Induces Endothelial Injury and Promotes Atherosclerosis.

The vascular response to pro-atherosclerotic factors is a multifactorial process involving endothelial cells (ECs), macrophages (MACs), and smooth muscle cells (SMCs), although the mechanism by which these cell types communicate with each other in response to environmental cues is yet to be understood. Here, we show that miR-155, which is significantly expressed and secreted in Krüppel-like factor 5 (KLF5)-overexpressing vascular smooth muscle cells (VSMCs), is a potent regulator of endothelium barrier function through regulating endothelial targeting tight junction protein expression. VSMCs-derived exosomes mediate the transfer of KLF5-induced miR-155 from SMCs to ECs, which, in turn, destroys tight junctions and the integrity of endothelial barriers, leading to an increased endothelial permeability and enhanced atherosclerotic progression. Moreover, overexpression of miR-155 in ECs inhibits endothelial cell proliferation/migration and re-endothelialization in vitro and in vivo and thus increases vascular endothelial permeability. Blockage of the exosome-mediated transfer of miR-155 between these two cells may serve as a therapeutic target for atherosclerosis.

[Effect of Qishen Yiqi droplet on adenylate contents in myocardium of cor pulmonale rats].

Cor pulmonale rat models were induced by a single intraperitoneal injection of monocrotaline(MCT), and the sham group received a single intraperitioneal injection of normal saline. After the model rats received intragastric administration of Qishen Yiqi droplet(QS) for 6 weeks, the contents of adenylate(ATP, ADP and AMP) in right myocardial tissues were measured by HPLC, and then the metabolism changes in myocardium of cor pulmonale rats with QS were investigated. The results showed that ATP, ADP, and AMP were well separated, with a good linearity within a certain range of concentration; and the recovery rates were within the range of 90%-108%. As compared with model group, the level of ATP was significantly elevated in high-dose treatment group; ADP contents showed an increasing trend and AMP contents showed a decreasing trend, indicating that QS could significantly improve energy metabolism system in myocardium. By using the HPLC, a qualitative and quantitative analysis method was given for the determination of ATP, ADP and AMP contents in myocardium, providing a method for energy metabolism measurement in biological samples.

miR-200c-SUMOylated KLF4 feedback loop acts as a switch in transcriptional programs that control VSMC proliferation.

The regulation of vascular smooth muscle cell (VSMC) proliferation is an important issue because it has major implications for the prevention of pathological vascular conditions. Using microRNA array screen, we found the expression levels of 200 unique miRNAs in hyperplasic tissues. Among them, miR-200c expression substantially was down-regulated. The objective of this work was to assess the function of miR-200c and SUMOylated Krϋppel-like transcription factor 4 (KLF4) in the regulation of VSMC proliferation in both cultured cells and animal models of balloon injury. Under basal conditions, we found that miR-200c inhibited the expression of KLF4 and the SUMO-conjugating enzyme Ubc9. Upon PDGF-BB treatment, Ubc9 interacted with and promoted the SUMOylation of KLF4, which allowed the recruitment of transcriptional corepressors (e.g., nuclear receptor corepressor (NCoR) and HDAC2) to the miR-200c promoter. The reduction in miR-200c levels led to increased target gene expression (e.g., Ubc9 and KLF4), which further repressed miR-200c levels and accelerated VSMC proliferation. These results demonstrate that induction of a miR-200c-SUMOylated KLF4 feedback loop is a significant aspect of the PDGF-BB proliferative response in VSMCs and that targeting Ubc9 represents a novel approach for the prevention of restenosis.

Tongxinluo (TXL), a Traditional Chinese Medicinal Compound, Improves Endothelial Function After Chronic Hypoxia Both In Vivo and In Vitro.

Vascular injury after chronic hypoxia leads to endothelial injury and structural damage to tight junctions (TJs), thereby resulting in a variety of cardiovascular diseases. Thus, attenuating hypoxia-induced damage has great significance for the prevention and treatment of cardiovascular disease. The aim of this study was to investigate whether the endothelial protection conferred by tongxinluo (TXL), a traditional Chinese medicinal compound, is related to its regulation of TJ protein expression. In vivo, we found that TXL could promote hypoxia-induced angiogenesis in lung and liver tissue. In vitro, we found that CoCl2 treatment significantly reduced the expression of the TJ proteins occludin, claudin-1, VE-cadherin, and beta-catenin in cultured human cardiac microvascular endothelial cells. TXL pretreatment abrogated the CoCl2-induced downregulation of these TJ proteins. Conversely, overexpression of Krüppel-like factor 4 (KLF4) inhibited the expression of TJ proteins in human cardiac microvascular endothelial cells, an effect that was reversed by TXL pretreatment. Further experiments showed that TXL could promote endothelial cell proliferation by increasing KLF4 phosphorylation, thereby reversing the effect of KLF4 on the expression of TJ proteins. These findings provide a new molecular mechanism for the TXL-induced increase in TJ protein expression.

[Effect of perinatal recurrent infection on the brain development in immature mice].

OBJECTIVE: To study the effects of perinatal recurrent infection on the brain development in immature mice. METHODS: Six pregnant C57BL6 mice were randomly assigned to three groups: intrauterine infection, perinatal recurrent infection and control. The intrauterine infection group was intraperitoneally injected with LPS (0.5 mg/kg) on the 18th day of pregnancy. The perinatal recurrent infection group was injected with LPS (0.5 mg/kg) on the 18th day of pregnancy and their offsprings were intraperitoneally injected with the same dose of LPS daily from postnatal day 3 to 12. The control group was administered with normal saline at the same time points as the recurrent infection group. The short-time neurobehaviors were assessed on postnatal day 13. The mice were then sacrificed to measure brain weights and neuropathological changes using cresyl violet staining. Western blot was used to evaluate the expression of TNF-α, Caspase-3 and myelin basic protein (MBP). RESULTS: The brain weights of the recurrent infection group were significantly lower than the control and intrauterine infection groups (P<0.05) and the recurrent infection group displayed significant neuropathological changes. Perinatal recurrent infection resulted in increased expression levels of TNF-α and Caspase-3, and decreased expression level of MBP compared with the intrauterine infection and control groups (P<0.01). The neurobehavior test showed that the recurrent infection group used longer time in gait reflex, right reflex and geotaxis reflex compared with the control and intrauterine infection groups on postnatal day 13 (P<0.05). CONCLUSIONS: Perinatal recurrent infection may exacerbate inflammatory response and cell death in the immature brain, which may be one of the important factors for perinatal brain injury.

Factors associated with infantile eczema in Hangzhou, China.

The removal of aggravating factors is important to reduce the severity of infantile eczema, but there are few studies on the assessment and identification of the aggravating factors in infantile eczema. Parents of children with infantile eczema ages 1 to 10 months (N = 250) were recruited. Parents were required to complete a questionnaire. Two hundred forty-two (96.8%) children had skin dryness, 80% bathed with soap or shower gel, 82% often perspired, 84.8% wore tight-fitting clothes, 80.8% dressed in five layers of thick clothing, 85.6% were in contact with wool or feathers, and 59.2% were exposed to sunlight (>20 minutes/day). Eczema severity was greater after vaccination in 20%. Two hundred thirty-five mothers avoided eating potential food allergens (e.g., milk, egg whites, and fish), but this failed to improve the severity of symptoms in 93.6% of the children. Thirty patients had Neocate as a substitute for cow's milk, which resulted in symptom severity improvement in 10%. Thirty children were given food allergens, which exacerbated symptoms in 13.3%. One hundred twenty-eight (51.2%) of the children were treated with corticosteroid ointment; 62.5% had the ointment applied for only 2 to 3 days, and 6.2% had the corticosteroid ointment applied to weeping lesions. The vast majority of parents did not know about the aggravating factors for infantile eczema. The results demonstrated a strong need for educational programs to help parents understand and control infantile eczema.

Angiotensin-converting enzyme 2 attenuates atherosclerotic lesions by targeting vascular cells.

Angiotensin-converting enzyme 2 (ACE2) is a newly discovered homolog of ACE whose actions oppose those of angiotensin II (AngII). However, the underlying mechanisms by which ACE2 effectively suppresses early atherosclerotic lesions remain poorly understood. Here, we show, both in vitro and in vivo, that ACE2 inhibited the development of early atherosclerotic lesions by suppressing the growth of vascular smooth muscle cells (VSMCs) and improving endothelial function. In a relatively large cohort animal study (66 rabbits), aortic segments transfected by Ad-ACE2 showed significantly attenuated fatty streak formation, neointimal macrophage infiltration, and alleviation of impaired endothelial function. Segments also showed decreased expression of monocyte chemoattractant protein 1, lectin-like oxidized low-density lipoprotein receptor 1, and proliferating cell nuclear antigen, which led to the delayed onset of atherosclerotic lesions. At the cellular level, ACE2 significantly modulated AngII-induced growth and migration in human umbilical vein endothelial cells and VSMCs. The antiatherosclerotic effect of ACE2 involved down-regulation of the ERK-p38, JAK-STAT, and AngII-ROS-NF-kappaB signaling pathways and up-regulation of the PI3K-Akt pathway. These findings revealed the molecular mechanisms of the antiatherosclerotic activity of ACE2 and suggested that modulation of ACE2 could offer a therapeutic option for treating atherosclerosis.

Natural Sesquiterpene Lactone as Source of Discovery of Novel Fungicidal Candidates: Structural Modification and Antifungal Activity Evaluation of Xanthatin Derived from Xanthium strumarium L.

As part of our ongoing efforts to discover novel agricultural fungicidal candidates from natural sesquiterpene lactones, in the present work, sixty-three xanthatin-based derivatives containing a arylpyrazole, arylimine, thio-acylamino, oxime, oxime ether, or oxime ester moiety were synthesized. Their structures were well characterized by 1H and 13C nuclear magnetic resonance and high-resolution mass spectrometry, while the absolute configurations of compounds 5' and 6a were further determined by single-crystal X-ray diffraction. Meanwhile, the antifungal activities of the prepared compounds against several phytopathogenic fungi were investigated using the spore germination method and the mycelium growth rate method in vitro. The bioassay results illustrated that compounds 5, 5', and 15 exhibited excellent inhibitory activity against the tested fungal spores and displayed remarkable inhibitory effects on fungal mycelia. Compounds 5 and 5' exhibited more potent inhibitory activity (IC50 = 1.1 and 24.8 µg/mL, respectively) against the spore of Botrytis cinerea than their precursor xanthatin (IC50 = 37.6 µg/mL), wherein the antifungal activity of compound 5 was 34-fold higher than that of xanthatin and 71-fold higher than that of the positive control, difenoconazole (IC50 = 78.5 µg/mL). Notably, compound 6'a also demonstrated broad-spectrum inhibitory activity against the four tested fungal spores. Meanwhile, compounds 2, 5, 8, and 15 showed prominent inhibitory activity against the mycelia of Cytospora mandshurica with the EC50 values of 2.3, 11.7, 11.1, and 3.0 µg/mL, respectively, whereas the EC50 value of xanthatin was 14.8 µg/mL. Additionally, compounds 5' and 15 exhibited good in vivo therapeutic and protective effects against B. cinerea with values of 55.4 and 62.8%, respectively. The preliminary structure-activity relationship analysis revealed that the introduction of oxime, oxime ether, or oxime ester structural fragment at the C-4 position of xanthatin or the introduction of a chlorine atom at the C-3 position of xanthatin might be significantly beneficial to antifungal activity. In conclusion, the comprehensive investigation indicated that partial xanthatin-based derivatives from this study could be considered for further exploration as potential lead structures toward developing novel fungicidal candidates for crop protection.

Dwarf apple MbDREB1 enhances plant tolerance to low temperature, drought, and salt stress via both ABA-dependent and ABA-independent pathways.

In higher plants, DREB1/CBF-type transcription factors play an important role in tolerance to low temperatures, drought, and high-salt stress. These transcription factors bind to CRT/DRE elements in promoter regions of target genes, regulating their expression. In this study, we cloned and characterized a novel gene encoding a DREB1 transcription factor from dwarf apple, Malus baccata (GenBank accession number: EF582842). Expression of MbDREB1 was induced by cold, drought, and salt stress, and also in response to exogenous ABA. Subcellular localization analyses revealed that MbDREB1 localizes in the nucleus. A yeast activity assay demonstrated that the MbDREB1 gene encodes a transcription activator, which specifically binds to DRE/CRT elements. Compared with wild-type plants, transgenic Arabidopsis overexpressing MbDREB1 showed increased tolerance to low temperature, drought, and salt stresses. Analysis of the MbDREB1 promoter revealed an ABA-responsive element (ABRE), an inducer of CBF expression 1 (ICE1)-like binding site, two MYB recognition sites, and three stress-inducible GT-1 boxes. GUS activities driven by the MbDREB1 promoter in transgenic Arabidopsis increased in response to ABA, cold temperature, drought, and salt treatments. Interestingly, the expression of both ABA-independent and ABA-dependent stress-induced genes (COR15a and rd29B, respectively) was activated under normal growth conditions in Arabidopsis overexpressing MbDREB1. These results suggest that MbDREB1 functions as a transcription factor and increases plant tolerance to low temperature, drought, and salt stress via both ABA-dependent and ABA-independent pathways.

Validation and reliability of distress thermometer in chinese cancer patients.

OBJECTIVE: To examine the validation and reliability of the distress thermometer (DT) recommended by National Comprehensive Cancer Network (NCCN) in Chinese cancer patients. METHODS: A total of 574 Chinese cancer patients from Beijing Cancer Hospital completed the detection of DT, the Hospital Anxiety and Depression Scale (HADS) and Symptom Checklist 90 (SCL-90), Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) were used to analyze the validation relative to HADS and SCL-90. The patients with DT≥4 and whose distress caused by emotional problems were interviewed with the MiNi International Neuro-psychiatric Interview (MINI) (Chinese Version 5.0). This version was used to analyze cancer patients' psychological and Psychiatric symptoms during the cancer process; 3. Another 106 cancer patients in rehabilitation stage and stable condition were asked to fill in DT two times, at the base time and after 7-10 days. RESULTS: Data of ROC indicates that a DT cutoff score of 4 yielded AUC of 0.80 with a optimal sensitivity (0.80) and specificity (0.70) relative to HADS, and AUC of 0.83 with the greatest sensitivity (0.87) and specificity (0.72) against SCL-90. The DT also has acceptable test-retest reliability (r=0.800, P=0.000); According to the interview results, the most common psychiatric problems cancer patients have adjustment disorder, depression, and anxiety. CONCLUSION: The data suggest that DT has acceptable overall accuracy and reliability as a screening tool for testing distress severity and specific problems causing distress in Chinese cancer patients. It is worth being used in oncology clinic, the rapid screening and interview could help caregivers to identify psychological and psychiatric problems of cancer patients and provide useful information for further treatment.

Atorvastatin combined with dexamethasone in chronic subdural haematoma (ATOCH II): study protocol for a randomized controlled trial.

BACKGROUND: Chronic subdural haematoma (CSDH) is a common condition in the elderly that often requires neurosurgical management. For small CSDH, evidence has emerged that statins may reduce haematoma volume and improve outcomes, presumably by reducing local inflammation and promoting vascular repair. We wish to extend this evidence in a study that aims to determine the efficacy and safety of atorvastatin combined with low-dose dexamethasone in patients with CSDH. METHODS: The second ATorvastatin On Chronic subdural Hematoma (ATOCH-II) study is a multi-centre, randomized, placebo-controlled, double-blind trial which aims to enrol 240 adult patients with a conservative therapeutic indication for CSDH, randomly allocated to standard treatment with atorvastatin 20 mg combined with low-dose dexamethasone (or matching placebos) daily for 28 days, and with 152 days of follow-up. The primary outcome is a composite good outcome defined by any reduction from baseline in haematoma volume and survival free of surgery at 28 days. Secondary outcomes include functional outcome on the modified Rankin scale (mRS) and modified Barthel Index at 28 days, surgical transition and reduction in haematoma volumes at 14, 28 and 90 days. DISCUSSION: This multi-centre clinical trial aims to provide high-quality evidence on the efficacy and safety of the combined treatment of atorvastatin and low-dose dexamethasone to reduce inflammation and enhance angiogenesis in CSDH. TRIAL REGISTRATION: ChiCTR, ChiCTR1900021659 . Registered on 3 March 2019, http://www.chictr.org.cn/showproj.aspx?proj=36157 .

A tetra-silver(I)ditungsten(VI) cluster with sulfide and bis-(diphenyl-phosphino)methane ligands.

The asymmetric unit of the title complex, [Ag(4)W(2)S(8)(C(25)H(22)P(2))(3)]·2C(3)H(7)NO, tris-[µ(2)-bis-(diphenyl-phosphino)meth-ane]-3:6κ(2)P:P';4:5κ(2)P:P';5:6κ(2)P:P'-µ(5)-sulfido-2:3:4:5:6κ(5)S-µ(3)-sulfido-1:3:4κ(3)S-tetra-µ(2)-sulfido-1:3κ(2)S;1:4κ(2)S;2:5κ(2)S;2:6κ(2)S-disulfido-1κS,2κS-tetra-silver(I)ditungsten(VI) N,N-dimethyl-formamide disolvate, contains two [WS(4)](2-) anions, four silver cations, three bidentate-bridging bis-(diphenyl-phosphino)methane (dppm) ligands and two N,N-dimethyl-formamide (DMF) solvent mol-ecules. The coordination geometry of each Ag atom is distorted tetra-hedral. Two Ag ions are coordinated by µ(2)-S and µ(5)-S atoms, and by two P atoms from two dppm ligands, while the other two Ag atoms are coordinated by µ(2)-S, µ(3)-S and µ(5)-S atoms, and by one P atom from a dppm ligand.

catena-Poly[silver(I)-bis-[µ-bis-(diphenyl-phosphino)methane-κP:P']-µ-thio-cyanato-κS:S-silver(I)-µ-thio-cyanato-κS:N].

The title compound, [Ag(NCS)(C(25)H(22)P(2))](n), contains two Ag(+) ions, two thio-cyanate ions and two bis-(diphenyl-phosphino)methane (dppm) ligands in the asymmetric unit. One of the thiocyanate ions bridges the two Ag(+) ions in a µ(2)-mode from its S atom and the two dppm ligands bridge the silver ions in a µ(1),µ(1) mode. The remaining SCN(-) ion bridges the binuclear units via its N and S atoms, generating a one-dimensional polymer propagating in [01]: the resulting AgP(2)SN and AgP(2)S(2) coordination geometries could be described as distorted tetra-hedral.

[Effects of gestational age on perinatal outcomes in patients complicated with early onset severe preeclampsia].

OBJECTIVE: To analysis the relationship between gestational age and perinatal outcomes in patients complicated with early onset severe preeclampsia. METHODS: Retrospective study was conducted on clinical documents of 221 patients with early onset severe preeclampsia (< 34 weeks) who delivered after 28 gestational weeks in Peking University First Hospital from July 1999 to June 2009. Patients were divided into three groups based on gestational weeks at delivery: group I (n = 81) delivered at 28 - 31 weeks(+6), group II (n = 78) at 32 - 33 weeks(+6) and group III (n = 62) after 34 weeks. The clinical characteristics and perinatal outcomes were compared among those three groups. RESULTS: (1) Outcome of neonates: Among 221 neonates, 13 neonates lost follow-up, including 9 in group I, 3 in group II, 1 in group III. The incidence of neonatal respiratory distress syndrome (RDS) of 26% (19/72) in group I were significantly higher than 7% (5/75) in group II and 10% (6/61) in group III (P < 0.05). The neonatal mortality rate of (43%, 31/72) in group I were significantly higher than 3% (2/61) in group III and 28% (21/75) in group II (P < 0.05). The incidence of maternal complications showed no statistical difference among three groups. (2) Neonatal death analysis: all neonatal death were due to parents' give up, including 26% (8/31) in group I, 67% (14/21) in group II and 1/2 in group III, which reached statistical difference (P < 0.05). CONCLUSIONS: The incidence of neonatal RDS in mother with early onset severe preeclampsia was decreased if delivered after 32 weeks, and the perinatal mortality was remarkably decreased if delivered after 34 weeks. Therefore, the perinatal survival rate in women with early onset severe preeclampsia can be improved by minimizing the impact of social factors.

[Representation, analysis and application of landscape graph based on graph theory]. / 基于图论的景观图表达、分析及应用.

Landscape structure and spatial pattern are the core issues in landscape ecology. The application of graph theory provides a research framework for landscape pattern analysis. Landscape graph based on graph theory is gradually applied to the connectivity modeling of biodiversity conservation and decision support of landscape planning. The representation, analysis and application of landscape graph have become a hot topic in conservation biology and landscape ecology. In this review, we first introduced the graph theory basis of landscape map. Based on the Scopus database, 257 published journal papers with the words "landscape graph", "connectivity" and "network" in titles, abstracts, and keywords from 1993 to 2019 were retrieved. We analyzed the research progress and development trend of this field from the aspects of annual published papers, journal sources, research areas, research institutions and landscape types involved. The results showed that before 2017, the number of journal papers published showed an overall increasing trend, and after 2017, the annual number of published papers decreased year by year. The main research forces were concentrated in United States, France, Canada, and China, contributing to 86.8% of the total published papers. Most of the research results were published in "Landscape Ecology", "Landscape and Urban Planning", and "Biological Conservation". In the research content, the representation of landscape graph mainly included the definition of nodes, the measurement of edges and the simulation of landscape. The analysis of landscape graph involved analysis index and landscape graph partitioning. This study mainly focused on the application of landscape graph in science and practice, including biodiversity conservation, landscape (ecological network) planning and management, the assessment of landscape impacts. Landscape graph based on graph theory influences conservation science and planning practitioners by helping understand landscape connectivity changes, animal behavior and habitat conservation. The impact of graph theory on conservation science and planning comes from the rich theoretical basis and mature research methods. Landscape graph based on graph theory provides a springboard for ecological understanding of landscape structure and pattern, and is an important tool for global researchers and practitioners.