Palladium(0) π-Lewis Base Catalysis: Concept and Development

The development of a new catalytic strategy plays a vital role in modern organic chemistry since it permits bond formation in an unprecedented and more efficient manner. Although the application of preformed metal complexes as π-base-activated reagents have enabled diverse transformations elegantly, the concept and strategy by directly utilizing transition metals as efficient π-Lewis base catalysts remain underdeveloped, especially in the field of asymmetric catalysis. Here, we outline our perspective on the discovery of palladium(0) as an efficient π-Lewis base catalyst, which is capable of increasing the highest occupied molecular orbital (HOMO) energy of both electron-neutral and electron-deficient 1,3-dienes and 1,3-enynes upon flexible η2-complexes formed in situ and resultant π-backdonation. Thus, fruitful carbon-carbon-forming reactions with diverse electrophiles can be achieved enantioselectively in a vinylogous addition pattern, which is conceptually different from the classical oxidative cyclization mechanism. Emphasis will be given to the concept and mechanism elucidation, catalytic features, and reaction design together with perspective on the further development of this emerging field.

Functional-Group-Directed Regiodivergent (3 + 2) Annulations of Electronically Distinct 1,3-Dienes and 2-Formyl Arylboronic Acids

Presented herein is a palladium-catalyzed asymmetric (3 + 2) annulation reaction between 1,3-dienes and 2-formylarylboronic acids, proceeding in a cascade vinylogous addition and Suzuki coupling process. Both electron-neutral and electron-deficient 1,3-dienes are compatible under similar catalytic conditions, and distinct regioselectivity is observed via functional-group control of 1,3-diene substrates. A collection of 1-indanols with dense functionalities is constructed stereoselectively.

Targeting cytohesin-1 suppresses acute myeloid leukemia progression and overcomes resistance to ABT-199

Adhesion molecules play essential roles in the homeostatic regulation and malignant transformation of hematopoietic cells. The dysregulated expression of adhesion molecules in leukemic cells accelerates disease progression and the development of drug resistance. Thus, targeting adhesion molecules represents an attractive anti-leukemic therapeutic strategy. In this study, we investigated the prognostic role and functional significance of cytohesin-1 (CYTH1) in acute myeloid leukemia (AML). Analysis of AML patient data from the GEPIA and BloodSpot databases revealed that CYTH1 was significantly overexpressed in AML and independently correlated with prognosis. Functional assays using AML cell lines and an AML xenograft mouse model confirmed that CYTH1 depletion significantly inhibited the adhesion, migration, homing, and engraftment of leukemic cells, delaying disease progression and prolonging animal survival. The CYTH1 inhibitor SecinH3 exerted in vitro and in vivo anti-leukemic effects by disrupting leukemic adhesion and survival programs. In line with the CYTH1 knockdown results, targeting CYTH1 by SecinH3 suppressed integrin-associated adhesion signaling by reducing ITGB2 expression. SecinH3 treatment efficiently induced the apoptosis and inhibited the growth of a panel of AML cell lines (MOLM-13, MV4-11 and THP-1) with mixed-lineage leukemia gene rearrangement, partly by reducing the expression of the anti-apoptotic protein MCL1. Moreover, we showed that SecinH3 synergized with the BCL2-selective inhibitor ABT-199 (venetoclax) to inhibit the proliferation and promote the apoptosis of ABT-199-resistant leukemic cells. Taken together, our results not only shed light on the role of CYTH1 in cell-adhesion-mediated leukemogenesis but also propose a novel combination treatment strategy for AML.

Palladium(0)-Catalyzed Enantioselective Construction of Multifunctional Piperidine Derivatives from 1,3-Dienes, N-Cyano Imines, and Beyond

An enantioselective (4 + 2) reaction between 1,3-dienes and N-cyano imines has been developed under Pd(0) catalysis, proceeding through a cascade vinylogous addition and intramolecular allylic amination sequence. 2,6-cis-Disubstituted-1,2,3,6-tetrahydropyridines were furnished as single diastereomers in moderate to good yields and enantiocontrol. Moreover, a more challenging three-component (2 + 2 + 2) annulation of 1,3-dienes, N-cyano imines, and activated alkenes was efficiently realized to afford piperidines with high structural complexity, albeit with moderate enantioselectivity.

Asymmetric Friedel-Crafts reaction of unsaturated carbonyl-tethered heteroarenes via vinylogous activation of Pd0-π-Lewis base catalysis

The alkyne group can undergo facile transformations under palladium catalysis, such as hydropalladation, Wacker reaction, etc. Here we demonstrate that a chiral Pd0 complex can chemoselectively dihapto-coordinate to the alkyne moiety of 2-indolyl propiolates, and raise the Highest Occupied Molecular Orbital (HOMO)-energy ofthe deactivated heteroarenes via π-Lewis base catalysis. As a result, asymmetric C3-selective Friedel-Crafts addition to activated alkenes occurs, finally affording [3 + 2] or [3 + 4] annulation products with high enantioselectivity and exclusive E-selectivity. Moreover, this π-Lewis base vinylogous HOMO-activation strategy can be extended to remote Friedel-Crafts reaction of diverse five-membered heteroarenes tethered to a 2-enone or 2-acrylate motif with imines or 1-azadienes, and excellent enantiocontrol is generally achieved for the multifunctional adducts, which can be effectively converted to diverse frameworks with higher molecular complexity. In addition, NMR and density functional theory calculation studies are conducted to elucidate the catalytic mechanism.

Estimating potassium in potato plants based on multispectral images acquired from unmanned aerial vehicles

Plant potassium content (PKC) is a crucial indicator of crop potassium nutrient status and is vital in making informed fertilization decisions in the field. This study aims to enhance the accuracy of PKC estimation during key potato growth stages by using vegetation indices (VIs) and spatial structure features derived from UAV-based multispectral sensors. Specifically, the fraction of vegetation coverage (FVC), gray-level co-occurrence matrix texture, and multispectral VIs were extracted from multispectral images acquired at the potato tuber formation, tuber growth, and starch accumulation stages. Linear regression and stepwise multiple linear regression analyses were conducted to investigate how VIs, both individually and in combination with spatial structure features, affect potato PKC estimation. The findings lead to the following conclusions: (1) Estimating potato PKC using multispectral VIs is feasible but necessitates further enhancements in accuracy. (2) Augmenting VIs with either the FVC or texture features makes potato PKC estimation more accurate than when using single VIs. (3) Finally, integrating VIs with both the FVC and texture features improves the accuracy of potato PKC estimation, resulting in notable R 2 values of 0.63, 0.84, and 0.80 for the three fertility periods, respectively, with corresponding root mean square errors of 0.44%, 0.29%, and 0.25%. Overall, these results highlight the potential of integrating canopy spectral information and spatial-structure information obtained from multispectral sensors mounted on unmanned aerial vehicles for monitoring crop growth and assessing potassium nutrient status. These findings thus have significant implications for agricultural management.

Asymmetric Construction of Multifunctional γ-Lactams from 1,3-Dienes and α-Ketoamides via Pd(0)-π-Lewis Base Catalysis

A straightforward approach for the asymmetric synthesis of multifunctionalized γ-lactams, including those bearing two tetrasubstituted stereogenic centers, has been developed through a palladium-catalyzed vinylogous addition/allylic amination process between 1,3-dienes and α-ketoamides. This protocol features advantages of ready substrate availability, broad applicability, high efficiency, and excellent stereoselectivity, making it an attractive complementary tool to the previous strategies.

Asymmetric 2,4-Dienylation/[4 + 2] Annulation Cascade to Construct Fused Frameworks via Auto-Tandem Palladium Catalysis

A palladium catalyzed tandem reaction between ortho-functionalized aryl enones and 2,4-dienyl carbonates has been presented, proceeding through sequential 2,4-dienylation/Michael addition/π-σ-π isomerization/allylic alkylation. A broad array of enantioenriched architectures having fused and spirocyclic frameworks are constructed in moderate to excellent yields and stereoselectivity. Notably, the intrinsic intramolecular Diels-Alder reaction pattern of the dienylated intermediates is well reversed via Pd(0)-π-Lewis base catalysis.

High-throughput and high-accuracy single-cell RNA isoform analysis using PacBio circular consensus sequencing

Although long-read single-cell RNA isoform sequencing (scISO-Seq) can reveal alternative RNA splicing in individual cells, it suffers from a low read throughput. Here, we introduce HIT-scISOseq, a method that removes most artifact cDNAs and concatenates multiple cDNAs for PacBio circular consensus sequencing (CCS) to achieve high-throughput and high-accuracy single-cell RNA isoform sequencing. HIT-scISOseq can yield >10 million high-accuracy long-reads in a single PacBio Sequel II SMRT Cell 8M. We also report the development of scISA-Tools that demultiplex HIT-scISOseq concatenated reads into single-cell cDNA reads with >99.99% accuracy and specificity. We apply HIT-scISOseq to characterize the transcriptomes of 3375 corneal limbus cells and reveal cell-type-specific isoform expression in them. HIT-scISOseq is a high-throughput, high-accuracy, technically accessible method and it can accelerate the burgeoning field of long-read single-cell transcriptomics.

Diastereodivergent cis- and trans-fused [4 + 2] annulations of cyclic 1,3-dienes and 1-azadienes via ligand-controlled palladium catalysis

Despite the blossoming of reports of diastereodivergent synthesis over the past years, switchable control of the stereochemistry of the bridgehead atoms of the fused frameworks has been significantly underdeveloped. Here we disclose the ability of Pd⁰-π-Lewis base catalysis to finely reverse the concerted inverse-electron-demand aza-Diels-Alder cycloaddition reaction between cyclic 1,3-dienes and aurone-derived 1-azadienes. In contrast, the in situ-formed HOMO-energy-increased Pd⁰-η²-complexes of cyclic 1,3-dienes underwent a cascade vinylogous Michael addition/allylic amination process with 1-azadienes. Moreover, judicious selection of chiral ligands allowed for switchable diastereodivergent [4 + 2] annulations to be accomplished, resulting in the construction of both cis- and trans-fused tetrahydropyridine architectures in high yields with moderate to excellent stereoselectivity levels. A variety of acyclic 1,3-dienes and 1-heterodienes were also applied, and furnished a structural diversity of enantioenriched frameworks.

Asymmetric Assemblies of 1,3-Dienes, Sulfuric Diamide, and Aldehydes to Access 1,3-Diamines through Relay Amine/Palladium Catalysis

A relay catalytic protocol using pyrrolidine and palladium catalysis has been developed for asymmetric synthesis of 1,3-diamine derivatives from 3-substituted 1,3-dienes, sulfuric diamide, and aldehydes. This one-pot, three-component reaction features the advantages of a high atom step economy and operational simplicity, providing an efficient and straightforward access to valuable 1,3-diamines incorporating quaternary and tertiary stereogenic centers with moderate to good enantioselectivity.

Formal nucleophilic pyrrolylmethylation via palladium-based auto-tandem catalysis: switchable regiodivergent synthesis and remote chirality transfer

Although nucleophilic benzylation-type reaction to introduce various aromatic systems into molecules has been widely explored, the related pyrrolylmethylation version remains to be disclosed. Reported herein is a palladium-catalysed multiple auto-tandem reaction between N-Ts propargylamines, allyl carbonates and aldimines in the presence of an acid, proceeding through sequential allylic amination, cycloisomerisation, vinylogous addition and aromatisation steps. A diversity of formal pyrrolylmethylated amine products were finally furnished efficiently. In addition, switchable regiodivergent 3-pyrrolylmethylation and 4-pyrrolylmethylation were realised by tuning catalytic conditions. Moreover, remote chirality transfer with readily available enantioenriched starting materials was well achieved with an achiral ligand, relying on diastereoselective generation of η2-Pd(0) complexes between Pd(0) and chiral 1,3-diene intermediates in the key vinylogous addition step. A few control experiments were conducted to elucidate the palladium-involved tandem reaction and regiodivergent synthesis.

The transplantation of rapamycin-treated senescent human mesenchymal stem cells with enhanced proangiogenic activity promotes neovascularization and ischemic limb salvage in mice

Few therapies can reverse the proangiogenic activity of senescent mesenchymal stromal/stem cells (MSCs). In this study, we investigated the effects of rapamycin on the proangiogenic ability of senescent human umbilical cord MSCs (UCMSCs). An in vitro replicative senescent cell model was established in cultured UCMSCs. We found that late passage (P25 or later) UCMSCs (LP-UCMSCs) exhibited impaired proangiogenic abilities. Treatment of P25 UCMSCs with rapamycin (900 nM) reversed the senescent phenotype and notably enhanced the proangiogenic activity of senescent UCMSCs. In a nude mouse model of hindlimb ischemia, intramuscular injection of rapamycin-treated P25 UCMSCs into the ischemic limb significantly promoted neovascularization and ischemic limb salvage. We further analyzed the changes in the expression of angiogenesis-associated genes in rapamycin-primed MSCs and found higher expression of several genes related to angiogenesis, such as VEGFR2 and CTGF/CCN2, in primed cells than in unprimed MSCs. Taken together, our data demonstrate that rapamycin is a potential drug to restore the proangiogenic activity of senescent MSCs, which is of importance in treating ischemic diseases and tissue engineering.

Cascade Multicomponent Assemblies Involving 1,3-Enynes via Auto-Tandem Palladium Catalysis

Here we report a three-component auto-tandem reaction of 1,3-enyne-tethered carbonyls, organoboronic reagents, and suitable nucleophiles catalyzed by palladium, proceeding through consecutive intramolecular vinylogous addition, Suzuki coupling, and allylic alkylation. This process exhibited high chemo- and regioselectivity with 1,3,4-trifunctionalization of the 1,3-enyne motif, and a wide range of 2H-chromenes, 1,2-dihydroquinolines, benzo[b]oxepines, 1,7-annulated indoles, and other frameworks were efficiently constructed in fair to good yields and E/Z selectivity.

Asymmetric Auto-Tandem Palladium Catalysis for 2,4-Dienyl Carbonates: Ligand-Controlled Divergent Synthesis

Developing new asymmetric auto-tandem catalysis processes, especially in a divergent manner, is highly attractive but extremely challenging. Presented herein is a palladium-catalyzed auto-tandem reaction between 2,4-dienyl carbonates and o-TsNH arylimines or trifluoroacetophenones that proceeds through a consecutive N-allylation, vinylogous addition, π-σ-π isomerization, and another N-allylation sequence. Importantly, switchable diastereodivergent synthesis could be achieved by tuning the chiral bisphosphine ligands, which led to the construction of a broad spectrum of fused tetrahydroquinoline architectures with moderate to excellent enantioselectivity. Ligand control even enabled effective access to regiodivergent azetidine or chemodivergent β-H elimination with fair enantioselectivity, further showing the versatility of the current auto-tandem catalysis.

The vascular risk factors and vascular neuropathology in subjects with autopsy-confirmed dementia with Lewy bodies

BACKGROUND

The frequency of vascular risk factors (VRFs) and the relationship between vascular pathology and cognitive function in neurodegenerative disease remains incompletely understood.

OBJECTIVE

The purpose of this study was to describe the frequency of VRFs and vascular pathology and explore the relationship between vascular pathology and cognitive function in dementia with Lewy bodies (DLB).

METHODS

This study included 363 autopsy-confirmed DLB and 753 Alzheimer's disease (AD) patients from the National Alzheimer's Coordinating Center (NACC) database. We used chi-squared test and analysis of variance to compare the VRFs and related factors in DLB and AD. Multinomial logistic regression and Spearman's correlation test were used to examine the relationship between vascular pathology and cognitive function.

RESULTS

No significant differences of VRFs were identified between DLB and AD. Alzheimer's disease patients had higher rates of microinfarcts (23.5% vs. 16.3%, p = 0.005) and moderate to severe amyloid angiopathy (45.9% vs. 36.1%, p = 0.002). In DLB patients, only cerebral amyloid angiopathy (CAA) pathology was negatively correlated with memory domain (r = -0.263, p < 0.001) and language (r = -0.112,p = 0.034). The rates of APOE ε4 allele carriers (60.0% vs. 44.9%, p = 0.004) and CAA pathology (45.9% vs.23.4%, p < 0.001) were much higher in the group with an intermediate likelihood of DLB than in the group with a high likelihood. There was a negative correlation between CAA pathology and memory (logical memory) in the group with an intermediate likelihood of DLB.

CONCLUSION

No difference of VRFs was identified between autopsy-confirmed DLB and AD. Cerebral amyloid angiopathy was shown to be an important pathology in DLB, which specifically correlated with memory and language. The groups with high and intermediate likelihood of DLB differed in terms of CAA pathology, and CAA pathology may play an important role in the development of DLB.

[Research progress on chemical constituents and biological activities of Sarcandra glabra]

Sarcandra glabra, a medicinal plant in family Chloranthaceae, has been taken as an important raw material for multiple Chinese patent drugs due to its diverse indications. Considering the diversified chemical constituents and rich biological activities of S. glabra, numerous phytochemical and pharmacodynamic investigations were conducted to explore the material basis for its medicinal use. It has been found that its main chemical constituents were sesquiterpenoids, sesquiterpenoid polymers, phenolic acids, coumarins, and flavonoids. As revealed by pharmacological research, it possesses multiple biological activities like anti-inflammation, anti-bacteria, anti-tumor, anti-oxidation, and neuroprotection. Some unreported novel structures, including polymers of lindenane sesquiterpenes and monoterpenes, sesquiterpene trimers, and adducts of flavonoids and monoterpenes, have been identified from S. glabra in recent years. Moreover, biological studies relating to its anti-tumor, anti-inflammatory, and anti-oxidant activities have been deepened. This paper reviewed the chemical constituents and bioactivities of S. glabra explored over the past ten years, so as to provide a scientific basis for further development and utilization of this plant.

Phosphine-catalysed intermolecular cyclopropanation reaction between benzyl bromides and activated alkenes

While phosphine-mediated reactions have been extensively explored over the past decades, the catalytic cyclopropanation reaction via a phosphonium ylide pathway has been significantly underdeveloped, and an intermolecular version still remains...

Chlomultiols A-L, sesquiterpenoids from Chloranthus multistachys and their anti-inflammatory activities

Twelve undescribed sesquiterpenoids, named chlomultiols A-L, involving three lindenane sesquiterpenoid dimers, three eudesmane sesquiterpenoids, three guaiane sesquiterpenoids, and three cadinane sesquiterpenoids, along with four known compounds, were obtained from the whole plant of Chloranthus multistachys. Their structures were determined through spectroscopic techniques (HRESIMS, 1D and 2D NMR). In addition, the absolute and relative configurations of the undescribed compounds were established by using single crystal X-ray crystallography, NOESY and CD spectroscopy. The inhibitory effects of chlomultiols A-M on the production of nitric oxide in RAW 264.7 cells induced by lipopolysaccharide were evaluated. Chlomultiols A-C, and chlomultiols K-L showed moderate anti-inflammatory activities with IC₅₀ values of 3.34 ± 0.73, 15.06 ± 1.08, 13.13 ± 3.99, 6.63 ± 1.11, and 16.16 ± 1.88 μM, respectively.

Association between marital status and cognitive impairment based on a cross-sectional study in China

BACKGROUND

Marital status may have an impact on the elderly population's health, but few studies in China discussed about the association between marital status and cognitive impairment.

OBJECTIVE

To investigate the relationship between marital status and cognitive impairment. To compare the influences of marital status on dementia between men and women.

METHODS

This study was based on a representative national cross-sectional epidemiological survey in China. We randomly selected 13 provinces and municipalities and included 19,276 participants aged 65 years or older in our study. Data was collected by interviewing the participants about their sociodemographic characteristics, and neuropsychological testing was administered to the participants by neurologists. To analyze the association between marital status and cognitive impairment, multiple logistic regression was based on a series of models.

RESULTS

Among the 19,276 subjects, about 77.2% were married, 1.6% were single, 21.2% were divorced/separated or widowed. The odds ratios (OR) of dementia were higher in single (OR: 2.13, CI: 1.53-2.97; p < 0.001), divorced/separated/widowed when they were ≤55 years old (OR: 1.75, CI: 1.30-2.35; p < 0.001), and divorced/separated/widowed when they were >55 years old (OR: 1.16, CI: 1.03-1.31; p < 0.001) participants than in married ones. Divorced/separated/widowed ≤55 men had about 2.75 times increase in dementia risk than married men.

CONCLUSION

People with long-term divorced/separated/widowed status would be associated to cognitive impairment more than those with short-term divorced/separated/widowed status. Men may be affected by marriage disruption more than women in terms of increasing the risk of dementia.

Asymmetric higher-order [10+n] cycloadditions of palladium-containing 10π-cycloaddends

We uncovered an asymmetric higher-order [10 + 2] cycloaddition reaction between diverse activated alkenes and a new type of π-allylpalladium complex-containing dipole-type 10π-cycloaddend, which was generated in situ from 2-methylene-1-indanols via a dehydrative insertion and deprotonation strategy under double activation of Pd(0) and phosphoric acid. A similar strategy was applied to an asymmetric higher-order [10 + 8] cycloaddition reaction or [10 + 4] cycloaddition reaction by using a heptafulvene derivative or a cyclic enone, respectively, as the acceptor. A variety of polycyclic frameworks imbedding an indene core were generally furnished in moderate to excellent yields with high levels of enantioselectivity by employing a newly designed chiral phosphoramidite ligand.

A type of π-allylpalladium complex-containing 10π-cycloaddend generated from 2-methylene-1-indanols under double activation of Pd(0) and phosphoric acid undergoes asymmetric higher-order [10 + 2] cycloadditions with diverse activated alkenes.

Construction of Hydrodibenzo[b,d]furan Frameworks from Morita-Baylis-Hillman Carbonates of Isatins and o-Hydroxy Enones via Palladium and Brønsted Base Relay Catalysis

A cascade assembly between isatin-derived Morita-Baylis-Hillman carbonates and o-hydroxybenzylideneacetones has been developed under the relay catalysis of Pd(PPh₃)₄ and DBU, affording a spectrum of 1,2,3,4-tetrahydrodibenzo[b,d]furan architectures incorporating a spirooxindole motif in moderate to good yields with excellent diastereoselectivity. The fused indole analogues were similarly furnished by employing the benzylideneacetones having an o-TsNH group.

[A new cembranoid diterpene from Olibanum]

Five compounds were isolated from the alcohol extract of Olibanum by MCI, silica gel, ODS, and Sephadex LH-20 column chromatographies and preparative high-performance liquid chromatography(HPLC). On the basis of spectral data and literature data, the compounds were identified as:(1S,3R,4S,7R,11S,12R)-1:12,4:7-diepoxisonane-8(19)-ene-3,11-diol(1), boscartin A(2),(+)-resinolin(3),(+)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one(4), and acerogenin A(5). Compound 1 is a new compound, and compounds 3-5 were isolated from Olibanum for the first time. The structure of compound 1 was determined by spectroscopic analysis and single-crystal X-ray diffraction. Compounds 1 and 2 were tested for PC12 neurotoxicity, and the results showed that they were both safe compounds.

Asymmetric [4 + 3] Annulations for Constructing Divergent Oxepane Frameworks via Cooperative Tertiary Amine/Transition Metal Catalysis

We report asymmetric [4 + 3] annulations between isatin-derived Morita-Baylis-Hillman carbonates and two types of vinyl carbonates synergistically catalyzed by tertiary amines and transition metals, through chemoselective assemblies of in situ formed allylic ylides and metal-containing 1,4-dipoles. A range of oxepane frameworks are generally constructed in moderate to good yields with high stereocontrol. Moreover, all four diastereomers for the products bearing vicinal stereocenters are accessible by tuning tertiary amine and metal catalysts.

[Research progress on chemical constituents from Chloranthus plants and their biological activities]

The genus Chloranthus has 13 species and 5 varieties in China, which can be found in the southwest and northeast regions. Phytochemical studies on Chloranthus plants have reported a large amount of terpenoids, such as diterpenoids, sesquiterpenoids, and sesquiterpenoid dimers. Their anti-inflammation, anti-tumor, antifungal, antivirus, and neuroprotection activities have been confirmed by previous pharmacological research. Herein, research on the chemical constituents from Chloranthus plants and their biological activities over the five years was summarized to provide scientific basis for the further development and utilization of Chloranthus plants.

[Chemical constituents of sesquiterpenes from Chloranthus multistachys]

With repeated silica gel, octadecyl silica(ODS), and Sephadex LH-20 column chromatography, normal-phase and reverse-phase high performance liquid chromatography(HPLC), etc., a pair of new enantiomers and 5 known compounds were separated from the 95% ethanol extract of Chloranthus multistachys. These compounds were identified by the nuclear magnetic resonance spectroscopy(including 1 D-NMR and 2 D-NMR), single-crystal X-ray diffraction, circular dichroism(CD) spectroscopy, mass spectrometry(MS), and some other methods as(1R,4R,5R,8S,10R)-chloraeudolide H(1 a),(1S,4S,5S,8R,10S)-chloraeudolide H(1 b), hydroxyisogermafurenolide(2), 4α-hydroxy-5α,8β(H)-eudesm-7(11)-en-8,12-olide(3), chloraniolide A(4), chlorantene D(5), 4α,8β-dihydroxy-5α(H)-eudesm-7(11)-en-8,12-olide(6). Compounds 1 a and 1 b are a pair of new eudesmane-type sesquiterpene enantiomers, and compounds 2-4 were isolated from C. multistachys for the first time.

[Association between pulse pressure and new-onset diabetes in hypertensive patients]

Objective: To determine the association between pulse pressure and the risk of new-onset diabetes in hypertensive patients. Methods: In this prospective cohort study, hypertensive patients from the Kailuan Study, who were diagnosed in 2006-2007 check-up, were screened for enrollment. Participants who finished the biennial follow-up until December 31, 2017 were finally included in this analysis. The primary outcome was incident diabetes development. The pulse pressure variables were divided into quartiles (Q1-Q4), and the Kaplan-Meier curve was used to examine and estimate the cumulative incidence of new-onset diabetes among quartiles. Cox proportional hazards regression model was performed to explore the association between pulse pressure and the risk of new-onset diabetes in hypertensive patients. Results: During an average follow-up of 8.17 years, 6 617 new-onset diabetes were identified out of the 32 917 hypertensive patients with no history or evidence of diabetes in 2006-2007 check-up. Participants were classified into quartiles according to pulse pressure levels as follows: Q1 group(<41 mmHg (1mmHg=0.133kPa))(n=7 995); Q2 group(41-<51 mmHg) (n=8 196); Q3 group (51-<61 mmHg) (n= 8 270); Q4 group (≥61 mmHg) (n=8 456). The cumulative incidences of new-onset diabetes across the quartiles were 16.94%, 19.61%, 21.07%, and 22.33%, respectively, with the incidence density was 20.27, 23.20, 24.92, and 26.10 per 1 000 person-years, respectively. The cumulative incidence of new-onset diabetes increased in proportion with increasing pulse pressure levels (P<0.01 by the Log-rank test). After multivariate adjustment, compared with the first quartile, the hazard ratios for new-onset diabetes in the third and fourth quartiles were 1.13 (95%CI 1.04-1.22, P<0.01) and 1.14 (95%CI 1.05-1.24, P<0.01), respectively. The risk of new-onset diabetes increased 5%(HR=1.05, 95%CI 1.02-1.08, P<0.01) with the fractional pulse pressure increased per 1 SD (0.13). Findings from the three sensitivity analyses were consistent with the main results in this cohort. Conclusions: Pulse pressure at baseline is positively associated with the incidence of new-onset diabetes among hypertensive individuals, and pulse pressure is an independent risk factor for the development of diabetes in hypertensive patients.

A Double Deprotonation Strategy for Cascade Annulations of Palladium-Trimethylenemethanes and Morita-Baylis-Hillman Carbonates to Construct Bicyclo[3.1.0]hexane Frameworks

Here we report that the chemoselective activation of Tsuji's 2-(cyanomethyl)allyl carbonates to generate the palladium-trimethylenemethane 1,3-dipoles via a deprotonation strategy can be realized in the presence of Morita-Baylis-Hillman carbonates from substantial activated ketones. The following S_N 2'-addition enables the formation of new 1,3-dipole species having an activated alkene moiety through a second deprotonation process, which then undergo cascade [1+2]/[3+2] annulations to furnish complex bicyclic [3.1.0]hexane frameworks having three contiguous quaternary stereogenic centers with good to excellent enantioselectivity. Moreover, by using benzoyl aldehyde-derived substrates, a [1+4]/[3+2] annulation sequence is similarly developed to produce fused cyclopenta[b]furan architectures.

Three pairs of sesquiterpene enantiomers from Chloranthus multistachys pei

Phytochemical investigation on the whole plant of Chloranthus multistachys pei (Chloranthaceae) afforded three pairs of new sesquiterpene enantiomers (+)/(-)-chlorantene M [(+)/(-)-1], (+)/(-)-chlorantene M1 [(+)/(-)-2] and (+)/(-)-chlorantene N [(+)/(-)-3]. The structures of new compounds were determined through spectroscopic techniques (HR-ESI-MS, 1 D and 2 D NMR), besides, their absolute and relative configurations were established by using Single-crystal X-ray diffraction analysis and CD spectrum. The anti-inflammatory potential of all compounds was evaluated by applying LPS induced RAW 264.7 macrophage inflammatory model, and the results were that none of these compounds showed activity (IC₅₀ > 100 μM).

[A new sesquiterpene from Chloranthus henryi]

Eight sesquiterpenes were isolated and purified from the ethanol extract of Chloranthus henryi by column chromatographies over silica gel, ODS and Sephadex LH-20,and preparative HPLC. Their chemical structures were established by spectral data and physiochemical properties as(1S,6S,8S,10R)-8-ethoxy-10-methoxychlomultin C(1),tianmushanol(2),multistalide A(3),myrrhterpenoid N(4),1α,9α-dihydroxy-8,12-expoxy-eudesma-4,7,11-trien-6-one(5),4β,10α-aromadendranediol(6),oplopanone(7),10α-hydroxycadinan-4-en-3-one(8). Among them, compound(1) was a new compound, and compounds 2-8 were isolated from Chloranthus henryi for the first time.

The Impact of the COVID-19 Pandemic and Lockdown on Mild Cognitive Impairment, Alzheimer's Disease and Dementia With Lewy Bodies in China: A 1-Year Follow-Up Study

Background: While the lockdown strategies taken by many countries effectively limited the spread of COVID-19, those were thought to have a negative impact on older people. This study aimed to investigate the impact of lockdown on cognitive function and neuropsychiatric symptoms over a 1-year follow-up period in patients with mild cognitive impairment (MCI), Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). Methods: We enrolled consecutive patients with MCI, probable AD or DLB who were receiving outpatient memory care before the COVID-19 pandemic and followed-up with them after 1 year by face-to-face during the COVID-19 pandemic to assess changes in physical activity, social contact, cognitive function and neuropsychiatric symptoms (NPS). Results: Total 105 probable AD, 50 MCI and 22 probable DLB patients were included and completed the 1-year follow-up between October 31 and November 30, 2020. Among the respondents, 42% of MCI, 54.3% of AD and 72.7% of DLB patients had a decline in MMSE scores and 54.4% of DLB patients had worsening Neuropsychiatric inventory (NPI) scores. Patients with DLB showed a more rapid decline of MMSE than those with AD. Diminished physical activity and social contact might have hastened the deterioration of cognition and the worsening of NPS. Conclusion: Social isolation and physical inactivity even after strict lockdown for at least 6 months were correlated with accelerated decline of cognitive function and NPS in patients with AD and DLB.

Palladium-catalysed oxidative nucleophilic allylation between alkenes and activated ketimines

A direct linear regioselective oxidative allylation reaction between alkenes and activated ketimines has been developed by using a Pd(OAc)2/2,6-dimethyl-1,4-benzoquinone system.

[Correlation of the peripheral serum complement protein levels and cognitive function in first-episode drug-naive patients with schizophrenia]

Objective: To explore the role of peripheral serum complement protein in the pathogenesis of cognitive impairment by analyzing the correlation between peripheral serum levels of complement protein and cognitive function in first-episode drug-naive patients with schizophrenia. Methods: A total of 66 first-episode drug-naive schizophrenics (schizophrenia group) from the Third Affiliated Hospital of Sun Yat-sen University and 88 healthy volunteers (control group) were enrolled. Peripheral serum levels of complements (C3, C4 and CH50) were separately examined by liposome immunoassay and turbidimetric inhibition immunoassay. The MATRICS Consensus Cognitive Battery (MCCB) was used to assess the cognitive function. Results: Peripheral serum levels of C4, but not C3 and CH50, were significantly lower in patients with schizophrenia [0.20(0.16, 0.25) g/L] than those in the control group [0.23 (0.19, 0.27) g/L] (P<0.05). Moreover the peripheral serum levels of C3, C4 and CH50 were positively correlated with MCCB verbal fluency (r=0.258, r=0.283 and r=0.330, all P<0.05), and the peripheral serum levels of CH50 were negatively correlated with attention and alertness (r=-0.257, P<0.05). Conclusion: The decrease of peripheral serum complement C4 protein levels may be involved in the mechamism of cognitive impairment in schizophrenia.

Mechanisms of Light-Induced Deformations in Photoreceptors

Biological cells deform on a nanometer scale when their transmembrane voltage changes, an effect that has been visualized during the action potential using quantitative phase imaging. Similar changes in the optical path length have been observed in photoreceptor outer segments after a flash stimulus via phase-resolved optical coherence tomography. These optoretinograms reveal a fast, millisecond-scale contraction of the outer segments by tens of nanometers, followed by a slow (hundreds of milliseconds) elongation reaching hundreds of nanometers. Ultrafast measurements of the contractile response using line-field phase-resolved optical coherence tomography show a logarithmic increase in amplitude and a decreasing time to peak with increasing stimulus intensity. We present a model that relates the early receptor potential to these deformations based on the voltage-dependent membrane tension-the mechanism observed earlier in neurons and other electrogenic cells. The early receptor potential is caused by conformational changes in opsins after photoisomerization, resulting in the fractional shift of the charge across the disk membrane. Lateral repulsion of the ions on both sides of the membrane affects its surface tension and leads to its lateral expansion. Because the volume of the disks does not change on a millisecond timescale, their lateral expansion leads to an axial contraction of the outer segment. With increasing stimulus intensity and the resulting tension, the area expansion coefficient of the disk membrane also increases as thermally induced fluctuations are pulled flat, resisting further expansion. This leads to the logarithmic saturation observed in measurements as well as the peak shift in time. This imaging technique therefore relates the structural changes in the photoreceptor to the underlying neurological function of transducing light into electrical signals. Such label-free optical monitoring of neural activity using fast interferometry may be applicable not only to optoretinography but also to neuroscience in general.

[Tap-hammer elicited vestibular-evoked myogenic potentials system: its design and preliminary application]

Objective: The aim of this study was to design and perform "Tap-hammer"system that can be used to elicit vestibular evoked myogenic potentials (VEMP) in normal adults and to report the preliminary results of this system. Methods: A triggered Tap-hammer was designed, made and connected with an electric recording system, to form as a system for Tap-VEMP recording. Twenty healthy adult volunteers (7 males and 13 females, aged 20 to 37 years, 40 ears in total) were recruited for air-conducted sound VEMP (ACS-VEMP) and Tap-VEMP examinations. Waveforms and parameters of both VEMPs were recorded and analyzed. SPSS 22.0 software was used for statistical analysis. Results: The response rates of ACS-, Tap-ocular VEMP (oVEMP) and ACS-, Tap-cervical VEMP (cVEMP) were both 100% (40/40). The mean±SD n1 latency, p1 latency, n1-p1 interval, amplitude, and asymmetry ratio (AR%) of Tap-oVEMP were (9.80±2.51)ms, (13.90±3.26)ms, (4.09±1.43)ms, (16.43±9.61)μV, (22.68±17.35)% respectively. The mean±SD p1 latency, n1 latency, p1-n1 interval, amplitude, and asymmetry ratio (AR%) of Tap-cVEMP were (13.26±2.07)ms, (21.84±2.89)ms, (8.58±2.10)ms, (457.65±274.94)μV, (20.42±13.46)% respectively. Both n1 latency and p1 latency of Tap-VEMPs were shorter than those in ACS-VEMPs (P<0.05). No statistical difference could be found between the two stimulation methods in the parameters of n1-p1 interval, amplitude, and asymmetry ratio(P>0.05). Conclusion: The Tap-hammer system can elicit VEMP responses in healthy young people. This system can be used as an alternative stimulation method for bone conduction VEMP.

Pseudo-Stereodivergent Synthesis of Enantioenriched Tetrasubstituted Alkenes by Cascade 1,3-Oxo-Allylation/Cope Rearrangement

The catalytic diastereodivergent construction of stereoisomers having two or more stereogenic centers has been extensively studied. In contrast, the switchable introduction of another stereogenic element, that is, Z/E configuration involving a polysubstituted alkene group, into the optically active stereoisomers, has not been recognized yet. Disclosed here is the pseudo-stereodivergent synthesis of highly enantioenriched tetrasubstituted alkene architectures from isatin-based Morita-Baylis-Hillman carbonates and allylic derivatives, under the cooperative catalysis of a tertiary amine and a chiral iridium complex. The success of the switchable construction of the tetrasubstituted alkene motif relies on the diastereodivergent 1,3-oxo-allylation reaction between N-allylic ylides and chiral π-allyliridium complex intermediates by ligand and substrate control, followed by the stereoselective concerted 3,3-Cope rearrangement process.

[Transbronchial lung cryobiopsy in diffuse lung disease: a pathological analysis of 173 cases]

Objective: To evaluate the value of transbronchial lung cryobiopsy (TBCB) in pathological diagnosis for diffuse lung disease. Methods: The clinicopathological data of 173 patients from the first affiliated hospital of Guangzhou medical university between Jaunary 2017 and June 2019 with transbronchial lung cryobiopsy of diffuse lung disease were retrospectively analyzed and summarized with review. Among 173 cases, TBCB and conventional transbronchial lung biopsy (TBLB) were performed in 54 patients. The size of biopsy samples and diagnostic yield were compared. Results: Among 173 cases, the diagnostic yield was 85.54% (148/173) , 160 (92.49%) cases provided definite diagnosis and valuable pathological results, according to age, sex, occupation, past history, contact history, smoking history, laboratory serology and imaging findings. Among 160 cases, there were 72 cases of known etiology (45.00%), 27 cases of idiopathic interstitial pneumonia (16.88%), 7 cases of granulomatous lesions (4.38%) and 54 cases of other types (33.75%). With TBCB and TBLB in 54 patients, the specimens sizes of TBCB and TBLB were (3.3±1.3) mm(2) and (1.0±0.3) mm(2) respectively (t'=12.67 P<0.01) . The diagnostic yields of TBCB and TBLB were 81.48% (44/54) and 42.59% (23/54) respectively (χ(2)=17.33, P<0.01) . The diagnostic yields of TBCB and TBLB for interstitial lung diseases were 48.15% (26/54) and 5.56% (3/54) respectively (χ(2)=24.94, P<0.01) . However, the diagnostic yields of TBCB and TBLB for the other diffuse lung disease except interstitial lung diseases were 33.33% (18/54) and 37.04% (20/54) respectively, with no significant difference (χ(2)=0.1624, P=0.687). Conclusion: Compared with TBLB, TBCB has obvious advantages and application value in the diagnosis of diffuse pulmonary diseases, especially interstitial pulmonary diseases.

Ultra-simple wearable local sweat volume monitoring patch based on swellable hydrogels

Quantifiably monitoring sweat rate and volume is important to assess the stress level of individuals and/or prevent dehydration, but despite intense research, a convenient, continuous, and low-cost method to monitor sweat rate and total sweat volume loss remains an un-met need. We present here an ultra-simple wearable sensor capable of measuring sweat rate and volume accurately. The device continuously monitors sweat rate by wicking the produced sweat into hydrogels that measurably swell in their physical geometry. The device has been designed as a simple to fabricate, low-cost, disposable patch. This patch exhibits stable and predictable operation over the maximum variable chemistry expected for sweat (pH 4-9 and salinity 0-100 mM NaCl). Preliminary in vivo testing of the patch has been achieved during aerobic exercise, and the sweat rates measured via the patch accurately follow actual sweat rates.

P3540The predictive value of global longitudinal strain in patients with heart failure mid-range ejection fraction

Background

Heart failure with mid-range ejection fraction (HFmrEF) was defined as the typical symptoms of HF with a left ventricular ejection fraction (LVEF) of 41% to 49%. However, till now the progression of LV function and the subsequent prognosis remains largely unknown. Speckle tracking echocardiography (STE) is a novel method to detect the early myocardial dysfunction and has been used to differentiate the outcomes of different phenotypes of cardiovascular diseases.

Purpose

Herein, we aim to investigate the application of STE in HFmrEF and its predictive values.

Methods

Retrospectively, we collected the medical records and echocardiography imaging of 250 patients diagnosed as HFmrEF during 2014 to 2018. LV longitudinal strain at diagnosis was evaluated and compared with the changes of LV during the follow-up period. Also, mortality and major adverse cardiovascular events (MACE) including myocardial infarction, heart failure requiring admission were recorded.

Results

Our result indicated that a reduced LV longitudinal strain at baseline was significantly associated with a subsequent declined LVEF beneath 40%. Also, the lower strain a baseline implied the higher mortality and MACE. Using −12% as the cut-off value LV strain presented the most significant impact on the prognosis compared with the other echocardiographic parameters in the logistic regression Regarding the guideline directed medications, blockers of renin-angiotensin-aldosterone system most significantly improved the cardiac remodeling compared with the others.

Conclusion

STE can predict the subsequent changes of LVEF and the cardiovascular outcomes in patients with HFmrEF.

P1569The Impact of Multidisciplinary Cardio-Oncology Program on the Cardiovascular Outcomes in Breast Cancer Patients

Background

Chemo- and target therapies may induce myocardial dysfunction and lead to poor prognoses. Early detection of minor myocardial dysfunction is important for the prevention of subsequent cardiotoxicity. Cardio-oncology is a multidisciplinary field focusing on managing and preventing cardiovascular complications in cancer patients. However, whether Cardio-oncology program truly makes difference in cardiovascular outcomes remains unknown. Herein, we are sharing our experiences in our Medical Center.

Methods

Since 2014 till 2017, we recruited 154 patients with newly diagnosed breast cancer preparing for Epirubicin therapy. Echocardiography, biomarkers, six minute walking distance and cardiovascular adverse events including new onset of hypertension, stroke, myocardial infarction (MI) and mortality were recorded at baseline, three months, six months and one year. Any functional decline was reported to oncologists for the consideration of changing regimens. Otherwise, cardiologists would be consulted for cardiovascular educations and therapies. The echocardiographic and clinical records of 450 breast patients receiving Epirubicin therapy during 2010 to 2013 were also collected as comparison.

Results

Compared with the ratio of 20% patients receiving echocardiography prior to 2014, the ratio increased to 100% since Cardio-Oncology program started. Also, the drop of left ventricular ejection fraction (LVEF) from 25% attenuated to 5%. Before Cardio-Oncology Program, there were 1.7% of new onset hypertension, 0.8% of MI, 0.8% of stroke and 16.8% of mortality. Conversely, after the program, there were only 0.6% of new onset hypertension while no other cardiovascular complications were reported. Furthermore, compared with previous reports of the effectiveness of Cardio-Oncology Program, our result also displayed a superior impact on the cardiovascular outcomes.

Conclusions

Collectively, through a comprehensive monitoring and an early intervention of myocardial dysfunction post chemotherapies, Cardio-Oncology Program truly decreased the cardiovascular complications in breast cancer patients.

Acknowledgement/Funding

Chi-Mei Medical Center

[Evaluation of vestibular evoked myogenic potential, caloric test and cochlear electrogram in the diagnosis of Meniere's disease]

Objective:The aim of this study is to evaluate the diagnostic value of vestibular-evoked myogenic potential （cVEMP and oVEMP）, caloric test, and cochlear electrogram （EcochG） in patients with Meniere's disease （MD） and non-Meniere's disease. Method:Sixty-four patients （64 ears） with Unilateral Meniere's disease were enrolled in the study group （MD group）, and 127 cases（254 ears） of non-Meniere's disease patients as non-MD group, including vertigo migraine in 40 cases, benign paroxysmal positional vertigo in 48 cases, benign recurrent vertigo in 13 cases, vestibular paroxysmia in 3 cases, vestibular neuritis in 5 cases and other undiagnosed vertigo in 18 cases. Both group undertake cVEMP, oVEMP, caloric test and ECochG. Use Medcale software to draw ROC curve of ECochG and calculate the area under curve（AUC）, Jordan index and optimal diagnostic cut-off points. Make the cut-off point as the point of -SP/AP, then evaluate the sensitivity, specificity, positive predictive value（PPV）, negative predictive value（NPV） and diagnostic accuracy of cVEMP, oVEMP, caloric test and ECochG in MD group and non-MD group. Result:The AUC of ECochG ROC curve was 0.74, the Jordan index was 0.47 and the cut-off point was 0.4. The sensitivity and specificity of cVEMP（62% and 68%）, oVEMP（61% and 53%） and caloric test（53% and 57%） were all below ECochG（65% and 78%）. The positive predictive value and of ECochG was the highest（61.9%）, the negative predictive value of cVEMP was highest（87.5%）. The diagnostic accuracy of ECochG was highest（74%）, followed with cVEMP（67%）, oVEMP（55%） and caloric test（56%）. Conclusion:Compared with the vestibular function tests, the sensitivity, specificity, diagnostic accuracy and NPV were all higher in ECochG, and the diagnostic benefit can be maximized when -SP/AP value>0.4. So the value of single vestibular function examination in the diagnosis of Meniere's disease is limited. The diagnosis of MD still requires a comprehensive evaluation in combination with medical history, audiological tests and vestibular function examinations.

[Preliminary observation of galvanic vestibular stimulation-vestibular evoked myogenic potentials in healthy young people]

Objective: To introduce the method of galvanic vestibular stimulation-vestibular evoked myogenic potentials (GVS-VEMP) as well as to observe and analyze the parameters and elicited rate of GVS-cVEMP and GVS-oVEMP in healthy young people in China. Methods: Twenty six normal young subjects were recruited for conventional examinations of GVS-VEMP. The subjects were 21-37 years old, average age was (25.8±3.7) years old, including 13 males and 13 females. The galvanic stimulation intensity of 3 mA/1 ms was used to evoke cVEMP and oVEMP on the sternocleidomastoid and inferior extraocular muscles respectively, and the intensity of stimulus was decreased until the response disappeared, the threshold, latency, amplitude, interval phase and interaural amplitude ratio(IAR) were calculated. SPSS18.0 software was used for statistical analysis. Results: All subjects were elicited normal GVS-cVEMP and GVS-oVEMP under 3 mA/1 ms, the elicited rate was 100%. The threshold of GVS-cVEMP was (1.18±0.47) mA, p1 latency was (10.43±1.54) ms, n1 latency was (17.91±1.20) ms, the amplitude was (102.47±56.77) uV and IAR was (0.26±0.20). The threshold of GVS-oVEMP was (1.12±0.50) mA, n1 latency was (8.46±1.05) ms, p1 latency was (11.83±1.27) ms, the amplitude was (9.12±6.82) uV and IAR was (0.25±0.20). In terms of gender and lateral comparison, only the GVS-oVEMP amplitude was higher for male than for female, which had significant statistical difference (P<0.05), and there was no statistical difference in the other parameters between GVS-cVEMP and GVS-oVEMP. Conclusion: GVS-cVEMP and GVS-oVEMP could be elicited in healthy youth population, and the parameters could provide reference for subsequent vestibular function evaluation.

[Functional vestibulo-ocular reflex test]

Summary In recent years, the diagnosis and treatment of vertigo and balance disorders have become a hot topic of multidisciplinary attention. The evaluation method of vestibular function has also been improved, providing important evidence for the diagnosis and differential diagnosis of vertigo related diseases. Vestibular rehabilitation is one of the important methods for the treatment of vertigo diseases. Assessing vestibular rehabilitation status in these patients is also the key for guiding treatment. The assessment of vestibulo-ocular reflex (VOR) function is an important part of vestibular functional testing. Currently, the dynamic visual acuity test (DVAT), gaze stabilization test (GST), and head impulse test (HIT) can be used to evaluate the VOR function. Based on these tests, a method of vestibular function testing has emerged internationally: functional head impulse test (fHIT). The article based on the review of relevant literatures and the principle of VOR detection and HIT detection to introduce the test methods and results interpretation of fHIT, DVAT and GST to provide reference for clinical diagnosis and treatment.

[Seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China]

Objective: To understand the seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China. Methods: This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout 7 geographic areas in the mainland of China (northeast, north, central, east, south, northwest and southwest). The numbers of asthmatic patients and total inpatients of the respiratory department of each hospital were recorded. The monthly ratio of asthmatic patients to the total inpatients in every area was calculated and compared. Results: During the study period, 6 480 patients were admitted for asthma exacerbation, accounting for 3.14% of all the 206 135 patients admitted to the respiratory departments in the 29 hospitals. The ratio of asthmatic patients to total inpatients in the northeast area (5.61%) was highest, and the ratio in east area was lowest (1.97%). Statistical analysis showed that the difference among different areas was significant (P<0.000 1). In most areas, both the number and proportion of hospitalized asthmatic patients peaked in spring (February-April) and autumn (September-October). In the northeast area, east area and south area, the peaks in spring were more obvious, while in the north area and southwest area, the peaks in autumn were more obvious. In the northwest area the peaks occurred in winter (December-January) and summer (June-August), respectively. The differences in hospitalization due to asthma among different months were significant in the northeast, north, and southwest areas (P<0.005). Conclusion: The number of patients hospitalized for asthma exacerbation fluctuated with season in different areas in China. In most areas, more asthmatic patients were admitted to hospitals in spring and autumn.