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1.
Chem Commun (Camb) ; 59(34): 5075-5078, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37021683

RESUMO

An unprecedented reductive aromatic C-H allylation reaction of benzyl electrophiles with allyl electrophiles has been established. A range of N-benzylsulfonimides smoothly participated in the palladium-catalyzed indium-mediated reductive aromatic C-H allylation with various allyl acetates, delivering structurally diverse allyl(hetero)arenes in moderate to excellent yields with good to excellent site selectivity. The use of inexpensive allyl esters for the reductive aromatic C-H allylation of N-benzylsulfonimides avoids the preparation of allyl organometallic reagents in advance and complements traditional functionalization of aromatic rings.

2.
EMBO J ; 42(3): e111304, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36477886

RESUMO

Parvalbumin-positive neurons (PVs) are the main class of inhibitory neurons in the mammalian central nervous system. By examining diurnal changes in synaptic and neuronal activity of PVs in the supragranular layer of the mouse primary visual cortex (V1), we found that both PV input and output are modulated in a time- and sleep-dependent manner throughout the 24-h day. We first show that PV-evoked inhibition is stronger by the end of the light cycle (ZT12) relative to the end of the dark cycle (ZT0), which is in line with the lower inhibitory input of PV neurons at ZT12 than at ZT0. Interestingly, PV inhibitory and excitatory synaptic transmission slowly oscillate in opposite directions during the light/dark cycle. Although excitatory synapses are predominantly regulated by experience, inhibitory synapses are regulated by sleep, via acetylcholine activating M1 receptors. Consistent with synaptic regulation of PVs, we further show in vivo that spontaneous PV activity displays daily rhythm mainly determined by visual experience, which negatively correlates with the activity cycle of surrounding pyramidal neurons and the dorsal lateral geniculate nucleus-evoked responses in V1. These findings underscore the physiological significance of PV's daily modulation.


Assuntos
Neurônios , Parvalbuminas , Animais , Camundongos , Parvalbuminas/metabolismo , Neurônios/metabolismo , Células Piramidais/metabolismo , Transmissão Sináptica , Sono , Mamíferos
3.
Org Biomol Chem ; 20(22): 4518-4521, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35604002

RESUMO

An unprecedented use of benzylsulfonyl hydrazides as benzylating agents has been demonstrated in the direct C-3 benzylation of quinoxalin-2(1H)-ones. A range of benzylsulfonyl hydrazides participated in the C-3 benzylation of quinoxalin-2(1H)-ones with CuCN as the catalyst and DTBP as the oxidant, delivering structurally diverse 3-benzylquinoxalin-2(1H)-ones in moderate to good yields.


Assuntos
Cobre , Quinoxalinas , Catálise , Hidrazinas , Estrutura Molecular
4.
Int J Hyperthermia ; 39(1): 155-161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35000496

RESUMO

OBJECTIVES: This study aimed to determine the performance of Sonazoid-based contrast-enhanced ultrasound (CEUS) in the microwave ablation (MWA) of primary hyperparathyroidism (pHPT). METHODS: Forty patients with pHPT were enrolled and treated with percutaneous ultrasound (US)-guided MWA assisted by CEUS. All patients underwent immediate CEUS examinations following MWA. On post-ablation day 1, patients who did not display a decrease in intact parathyroid hormone (iPTH) levels to the norm were examined by CEUS to evaluate an incomplete ablation. We compared the serum iPTH and calcium levels and the nodule volumes before and after MWA. The complications were evaluated during and after treatment. RESULTS: Immediately following MWA, CEUS demonstrated complete ablation with all 44 parathyroid nodules. On post-ablation day 1, five nodules in five patients displayed annular enhancement around the ablation zone on CEUS. The average maximum diameters of the nodules and the ablation zone were 1.09 ± 0.28 cm and 1.36 ± 0.23 cm, respectively. An ablation zone larger than the primary lesion (p < 0.05) generated a higher rate of complete ablation. Compared with pre-MWA, serum iPTH and calcium levels were significantly improved. Treatment success was achieved in 38 patients (95%). Hoarseness was a major complication in six patients (15%); however, it improved spontaneously within 1-4 months. We observed two recurrences (2/40, 5%) at 9 months and 11 months following MWA, respectively. CONCLUSION: US-guided percutaneous MWA assisted by CEUS for pHPT is an effective and safe therapy. CEUS can avoid operative failure and improve the cure rate.


Assuntos
Hiperparatireoidismo Primário , Compostos Férricos , Humanos , Hiperparatireoidismo Primário/diagnóstico por imagem , Hiperparatireoidismo Primário/cirurgia , Ferro , Micro-Ondas , Óxidos , Estudos Retrospectivos , Ultrassonografia , Ultrassonografia de Intervenção
5.
Org Biomol Chem ; 19(24): 5353-5357, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34047329

RESUMO

An unprecedented [2,3]-sigmatropic rearrangement reaction of quaternary 2,3-allenylammonium ylides, generated in situ from tertiary 2,3-allenylamines and arynes, has been established. With 2-(trimethylsilyl)aryl triflates as aryne precursors, a range of tertiary 2,3-allenylamines bearing an electron-withdrawing group at the α-position smoothly participated in the aryne-mediated [2,3]-sigmatropic rearrangement at room temperature, delivering structurally diverse 2-vinylallyamines or 1-amino-1,3-dienes in moderate to excellent yields. The reaction proceeds in the absence of strong bases and transition metals, is compatible with moisture and air, and tolerates a wide variety of functional groups.

7.
Chemistry ; 27(9): 3091-3097, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33205537

RESUMO

The charge-accelerated aza-Claisen rearrangement of ammonium salts serves as a key step in the construction of complex nitrogen-containing molecules. However, much less attention has been paid to the aromatic aza-Claisen rearrangement than to the aliphatic one. Herein, we report an unprecedented aromatic aza-Claisen rearrangement of arylpropargylammonium salts, generated in situ from arynes and tertiary propargylamines, delivering structurally diverse 2-propargylanilines in moderate to good yields with high regioselectivity. This rearrangement proceeds in the absence of strong bases or transition metals, is compatible with moisture and air, tolerates a wide variety of functional groups, and is amenable to forming 11- to 13-membered heterocycles with a triple bond. The 2-propargylaniline products were treated with aluminum chloride in ethanol to afford multisubstituted indoles in moderate to excellent yields. Finally, a series of deuterium-labeling experiments was performed to elucidate the reaction mechanism.

8.
Physiol Behav ; 223: 113004, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32525009

RESUMO

Recently, short-chain fatty acids (SCFA) have been shown to play an important role in mediating the gut-brain interaction and thereby participate in the patho-physiological process of stress-related disorders. In the current study, we examined whether SCFA generated in the lower gut affects host metabolic and behavioral characteristics. To determine this, we used special diets containing acylated starches that can reach the colon without being absorbed in the upper gastrointestinal tract of male mice. The delivery of SCFA to the colon using this method induced a substantial increase in acetate, butyrate, and propionate in the cecum. Moreover, the diets containing acylated starches also decreased microbial diversity in the cecum, concomitant with a significant impact on microbial composition. In marble-burying (MB) tests, the mice that consumed diets containing acetylated starches showed a decrease in anxiety-like behavior compared with the mice that consumed diets containing either butyrylated or propionylated starches. Cecal acetate contents were significantly associated with anxiety-like behaviors when evaluated by elevated plus-maze and MB tests. Collectively, these results indicate that gut acetate elevation of a dietary origin may exert anxiolytic effects on behavioral phenotypes of the host.


Assuntos
Ansiolíticos , Acetatos , Animais , Colo , Dieta , Ácidos Graxos Voláteis , Masculino , Camundongos
9.
Neuron ; 105(4): 621-629.e4, 2020 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-31831331

RESUMO

A balance between synaptic excitation and inhibition (E/I balance) maintained within a narrow window is widely regarded to be crucial for cortical processing. In line with this idea, the E/I balance is reportedly comparable across neighboring neurons, behavioral states, and developmental stages and altered in many neurological disorders. Motivated by these ideas, we examined whether synaptic inhibition changes over the 24-h day to compensate for the well-documented sleep-dependent changes in synaptic excitation. We found that, in pyramidal cells of visual and prefrontal cortices and hippocampal CA1, synaptic inhibition also changes over the 24-h light/dark cycle but, surprisingly, in the opposite direction of synaptic excitation. Inhibition is upregulated in the visual cortex during the light phase in a sleep-dependent manner. In the visual cortex, these changes in the E/I balance occurred in feedback, but not feedforward, circuits. These observations open new and interesting questions on the function and regulation of the E/I balance.


Assuntos
Ritmo Circadiano/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciais Pós-Sinápticos Inibidores/fisiologia , Rede Nervosa/fisiologia , Córtex Visual/fisiologia , Vias Visuais/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Rede Nervosa/citologia , Inibição Neural/fisiologia , Técnicas de Cultura de Órgãos , Células Piramidais/fisiologia , Córtex Visual/citologia , Vias Visuais/citologia
10.
Zhongguo Zhong Yao Za Zhi ; 44(17): 3732-3737, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31602946

RESUMO

Grade evaluation method of quality constant is a kind of grading method for Chinese medicinal materials and decoction pieces,combining the external morphological index and internal content index. This method was used in this paper for grade evaluation of Gardeniae Fructus. By measuring the morphological and content indexes of 14 batches of Gardeniae Fructus,a method for calculating the quality constant of fruits was established,and the grade evaluation criteria were formed. At the same time,the NO inhibition effect of different grades of Gardeniae Fructus samples on RAW264. 7 cells induced by LPS was determined to investigate the relationship between the quality grade and pharmacodynamics of decoction pieces. The results showed that the quality constants of Gardeniae Fructus decoction piece samples ranged from 1. 46 to 4. 42. If the percentage quality constant ≥80% was classified into first-class,50%-80%as second-class and the rest as third-class,the quality constant was ≥3. 54 for first-class,2. 21-3. 54 for second-class and <2. 21 for third-class Gardeniae Fructus decoction pieces. The pharmacodynamic results showed that the pharmacodynamic intensity was positively correlated with the grade,which also proved the rationality of the grade evaluation method of quality constant.


Assuntos
Medicamentos de Ervas Chinesas/normas , Frutas/química , Gardenia/química , Animais , Medicamentos de Ervas Chinesas/análise , Camundongos , Controle de Qualidade , Células RAW 264.7
11.
Endocrinology ; 160(10): 2441-2452, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504398

RESUMO

Anorexia nervosa (AN) results in gut dysbiosis, but whether the dysbiosis contributes to AN-specific pathologies such as poor weight gain and neuropsychiatric abnormalities remains unclear. To address this, germ-free mice were reconstituted with the microbiota of four patients with restricting-type AN (gAN mice) and four healthy control individuals (gHC mice). The effects of gut microbes on weight gain and behavioral characteristics were examined. Fecal microbial profiles in recipient gnotobiotic mice were clustered with those of the human donors. Compared with gHC mice, gAN mice showed a decrease in body weight gain, concomitant with reduced food intake. Food efficiency ratio (body weight gain/food intake) was also significantly lower in gAN mice than in gHC mice, suggesting that decreased appetite as well as the capacity to convert ingested food to unit of body substance may contribute to poor weight gain. Both anxiety-related behavior measured by open-field tests and compulsive behavior measured by a marble-burying test were increased only in gAN mice but not in gHC mice. Serotonin levels in the brain stem of gAN mice were lower than those in the brain stem of gHC mice. Moreover, the genus Bacteroides showed the highest correlation with the number of buried marbles among all genera identified. Administration of Bacteroides vulgatus reversed compulsive behavior but failed to exert any substantial effect on body weight. Collectively, these results indicate that AN-specific dysbiosis may contribute to both poor weight gain and mental disorders in patients with AN.


Assuntos
Anorexia Nervosa/microbiologia , Comportamento Animal , Microbioma Gastrointestinal , Aumento de Peso , Adulto , Animais , Transplante de Microbiota Fecal , Feminino , Vida Livre de Germes , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Adulto Jovem
12.
Medicine (Baltimore) ; 98(18): e15150, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31045758

RESUMO

RATIONALE: Deep benign fibrous histiocytoma (BFH) is relatively rare in contrast to superficial BFH involving the skin. Moreover, it was extremely rare for deep BFH occurring in the solid organ. To our knowledge, so far, only one case of deep BFH of the kidney was reported in English literature. PATIENT CONCERNS: Herein, we report another case of deep BFH located in the kidney in a 88-year-old female. She was referred to our hospital for a severe pain in the right upper abdomen. Computed tomography revealed a round low-density shadow measuring 6 cm in the kidney. DIAGNOSIS: The lesion was diagnosed as a deep BFH of the kidney, as the tumor was histologically predominately composed of bland ovoid cells arranged in a storiform pattern. INTERVENTION: The patient underwent the total resection of the right kidney with the tumor in our hospital. OUTCOMES: The postoperative course was uneventful. The patient was alive with no tumor recurrence or metastasis within 6 months of follow-up. LESSONS: We present another case of deep BFH of the kidney. Because of the rarity, the tumor may be poorly recognized. The typical storiform pattern in histology may be helpful for diagnosis. This report serves to remind that deep BFH is also a differential diagnosis for a tumor with storiform pattern in the kidney.


Assuntos
Dor Abdominal/etiologia , Histiocitoma Fibroso Benigno/patologia , Rim/patologia , Dor Abdominal/diagnóstico , Assistência ao Convalescente , Idoso de 80 Anos ou mais , Feminino , Histiocitoma Fibroso Benigno/diagnóstico por imagem , Histiocitoma Fibroso Benigno/cirurgia , Histiocitoma Fibroso Benigno/ultraestrutura , Humanos , Rim/diagnóstico por imagem , Rim/cirurgia , Neoplasias de Tecidos Moles/patologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
13.
Int J Clin Exp Pathol ; 12(4): 1118-1123, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31933927

RESUMO

Pleomorphic xanthoastrocytoma (PXA) is a relatively rare, low grade astrocytic tumor that usually affects children as well as young adults. The reported cases were predominantly located superficially in the temporal lobe. To our knowledge, so far only two cases of PXA occurring in lateral ventricle were reported in English literature. Herein, we present the third case of PXA intra-lateral ventricle in a 28-year-old Chinese male. Histologically, the tumor was relatively well circumscribed and consisted of spindle-shaped, ovoid, and multinuclear giant cells admixed with scattered eosinophilic granular bodies, inflammatory cells, and xanthomatous cells. Immunohistochemically, the tumor cells were strongly positive for S-100, GFAP, oligo-2 and vimentin, focally positive for synaptophysin and CD34, and negative for cytokeratin, EMA, NeuN and IDH1. Ki-67 proliferation index was approximately 2%. A BRAF V600E mutation was then identified in the tumor. Based on morphologic features, the immunohistochemical staining and BRAF V600E mutation, the tumor was diagnosed as a PXA. Because of the presence of the bizarre multinuclear giant cells and xanthomatous cells and the unusual location, PXA was easily misdiagnosed as a high-grade tumor. It should be noted that PXA was also an important differential diagnosis for intraventricular tumors.

14.
Medicine (Baltimore) ; 97(18): e0661, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29718888

RESUMO

RATIONALE: Placental transmogrification of the lung is a very rare lesion which was characterized by the presence of papillae resembling placental villi. Its pathogenesis still remains unclear. Some authors think that this lesion is congenital and related to hamartoma, and others advocate it is secondary change after emphysema. So far, the majority of reported cases manifested as bullous lesions, to our knowledge , only two cases presented as a solitary nodule. PATIENT CONCERNS: Herein, we report the third case presenting as a small nodule in a 49-year-old male. Chest computed tomography revealed a nodular shadow measuring 2.6 × 1.2 cm in the right lower lobe of the lung. Histologically, the tumor composed of papillary structures covered by cuboidal pneumocytes and bland clear cells and abundant capillaries in the stroma. DIAGNOSIS: The lesion was diagnosed as a placental transmogrification of the lung. INTERVENTION: The patient then underwent wedge resection in our hospital. OUTCOMES: The postoperative course was uneventful. LESSONS: The patient had a history of traffic accident half a year before the nodule was detected. This prompts placental transmogrification of the lung may at least partially represent a acquired malformation. The present case aims to raise a new suggestion for its possible nature. In our opinion, PT may simply represent a benign morphologic change rather than an independent disease. It may be encountered in both congenital and secondary lesions.


Assuntos
Lesão Pulmonar/complicações , Pulmão , Pneumonectomia/métodos , Enfisema Pulmonar , Nódulo Pulmonar Solitário/diagnóstico , Acidentes de Trânsito , Diagnóstico Diferencial , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Enfisema Pulmonar/diagnóstico por imagem , Enfisema Pulmonar/patologia , Enfisema Pulmonar/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Resultado do Tratamento
15.
Medicine (Baltimore) ; 97(3): e9597, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29504983

RESUMO

RATIONALE: Mucous gland adenoma is an extremely rare benign tumor predominately presented in central bronchus. Thus far, only six cases located in the periphery have been reported in English literature. PATIENT CONCERNS: Herein, we report a case located in periphery of the lung with parenchymal involvement in a 59-year-old female. Histologically, the tumor appeared as peripheral lobulated and solid mass with the pushing border. The tumor was composed of abundant irregular glands, mucus-filled acini and tubules lined by bland cuboidal to columnar mucus-secreting epithelial cells lacking cellular atypia and mitotic activities. Moreover, the tumor contained fibromyxoid stroma with smooth muscular bundles and prominent lymph follicles, which has not been reported in previous cases. DIAGNOSIS: Based on the morphological profile and immunohistochemical staining, the tumor was diagnosed as a mucous gland adenoma. INTERVENTION: The patient then underwent wedge resection in our hospital. OUTCOMES: The patient was alive with no tumor recurrence or metastasis within 16 months of follow-up. LESSONS: We report a peculiar case of mucous gland adenoma that occurred in the periphery of the lung and involved the parenchyma. The present case reported the smooth muscular bundles presenting in the stroma, which could broaden the histologic profile of the tumor.


Assuntos
Adenoma/patologia , Neoplasias Pulmonares/patologia , Músculo Liso/patologia , Feminino , Humanos , Pessoa de Meia-Idade
16.
PLoS One ; 12(7): e0180745, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28683093

RESUMO

Gut lumen serotonin (5-hydroxytryptamine: 5-HT) contributes to several gastrointestinal functions such as peristaltic reflexes. 5-HT is released from enterochromaffin (EC) cells in response to a number of stimuli, including signals from the gut microbiota. However, the specific mechanism by which the gut microbiota regulates 5-HT levels in the gut lumen has not yet been clarified. Our previous work with gnotobiotic mice showed that free catecholamines can be produced by the deconjugation of conjugated catecholamines; hence, we speculated that deconjugation by bacterial enzymes may be one of the mechanisms whereby gut microbes can produce free 5-HT in the gut lumen. In this study, we tested this hypothesis using germ-free (GF) mice and gnotobiotic mice recolonized with specific pathogen-free (SPF) fecal flora (EX-GF). The 5-HT levels in the lumens of the cecum and colon were significantly lower in the GF mice than in the EX-GF mice. Moreover, these levels were rapidly increased, within only 3 days after exposure to SPF microbiota. The majority of 5-HT was in an unconjugated, free form in the EX-GF mice, whereas approximately 50% of the 5-HT was found in the conjugated form in the GF mice. These results further support the current view that the gut microbiota plays a crucial role in promoting the production of biologically active, free 5-HT. The deconjugation of glucuronide-conjugated 5-HT by bacterial enzymes is likely one of the mechanisms contributing to free 5-HT production in the gut lumen.


Assuntos
Mucosa Intestinal/metabolismo , Microbiota , Serotonina/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Vida Livre de Germes , Intestinos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
World J Gastroenterol ; 23(2): 242-255, 2017 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-28127198

RESUMO

AIM: To investigate the protective effect of a recombinant adeno-associated virus carrying thymosin ß4 (AAV-Tß4) on murine colitis via intracolonic administration. METHODS: AAV-Tß4 was prepared and intracolonically used to mediate the secretory expression of Tß4 in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn's disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tß4 on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively. RESULTS: Recombinant AAVs efficiently delivered LacZ and Tß4 into the colonic tissues of the mice, and AAV-Tß4 led to a strong expression of Tß4 in mouse colons. In both the DSS and TNBS colitis models, AAV-Tß4-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tß4 significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tß4 also modulated colonic TNF-α, IL-1ß and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice. CONCLUSION: Tß4 exerts a protective effect on murine colitis, indicating that AAV-Tß4 could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.


Assuntos
Colite Ulcerativa/metabolismo , Colo/metabolismo , Doença de Crohn/metabolismo , Mucosa Intestinal/metabolismo , Timosina/metabolismo , Animais , Proliferação de Células , Colite Ulcerativa/induzido quimicamente , Colo/enzimologia , Doença de Crohn/induzido quimicamente , DNA Recombinante/administração & dosagem , Dependovirus/genética , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Enterócitos/metabolismo , Enterócitos/fisiologia , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos/administração & dosagem , Imunoquímica , Interleucina-10/metabolismo , Interleucina-1beta/metabolismo , Mucosa Intestinal/citologia , Mucosa Intestinal/enzimologia , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo , Superóxido Dismutase/metabolismo , Ácido Trinitrobenzenossulfônico/toxicidade , Fator de Necrose Tumoral alfa/metabolismo
18.
Ying Yong Sheng Tai Xue Bao ; 27(7): 2264-2272, 2016 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-29737135

RESUMO

Based on the field experiment which was conducted in Dingxi County of Gansu Province, and involved in the three treatments: (1) plastic mulching on entire land with soil coverage and bunching (PMS), (2) plastic mulching on entire land and bunching (PM), and (3) direct bunching without mulching (CK). The parameters of SPAD values, chlorophyll fluorescence parameters, photosynthetic gas exchange parameters, as well as leaf area index (LAI), yield, evapotranspiration, and water use efficiency in flag leaves of spring wheat were recorded and analyzed from 2012 to 2013 continuously. The results showed that SPAD values of wheat flag leaves increased in PMS by 10.0%-21.5% and 3.2%-21.6% compared to PM and CK in post-flowering stage, respectively. The maximum photochemical efficiency (Fv/Fm) , actual photochemical efficiency (ΦPS2) of photosystem 2 (PS2), and photochemical quenching coefficient (qP) of PMS were higher than those of PM and CK, the maximum increment values were 6.1%, 9.6% and 30.9% as compared with PM, and significant differences were observed in filling stage (P<0.05). The values of qN in PMS were lowest among the three treatments, and it decreased significantly by 23.8% and 15.4% in heading stage in 2012 and 2013 respectively, as compared with PM. The stoma conductance (gs) of wheat flag leaves in PMS was higher than that of PM and CK, with significant difference being observed in filling stage, and it increased by 17.1% and 21.1% in 2012 and 2013 respectively, as compared with PM. The transpiration rate (Tr), net photosynthetic rate (Pn), and leaf instantaneous water use efficiency (WUEi) except heading stage in 2013 of PMS increased by 5.4%-16.7%, 11.2%-23.7%, and 5.6%-7.2%, respectively, as compared with PM, and significant difference of WUEi was observed in flowering stage in 2012. The leaf area index (LAI) of PMS was higher than that of PM and CK, especially, it differed significantly in seasonal drought of 2013. Consequently, the PMS increased the SPAD values in flag leaves of spring wheat, and the capacity of flag leaves for photo energy assimilation and photosynthetic gas exchange were enhanced, caused more photosynthetic energy flowing into photochemical process, as well as decreased the heat dissipation, resulted in the increment of Pn and WUEi. Based on the higher Pn and LAI, the yield and WUE of PMS increased.


Assuntos
Agricultura/métodos , Fotossíntese , Triticum/fisiologia , Água/fisiologia , Clorofila , Secas , Complexo de Proteína do Fotossistema II , Folhas de Planta , Transpiração Vegetal , Plásticos , Chuva , Estações do Ano , Solo
19.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 11): m1528, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22219774

RESUMO

In the title compound, [Cu(C(4)H(5)O(4))(H(2)O)](n), the imino-diacetate (ida) ligands link the Cu(II) atoms into polymeric zigzag chains running along [010]. Each Cu(II) ion is five-coordinated in a distorted square-pyramidal geometry by one N and two O atoms from an ida ligand, one O atom from the neighbouring ida ligand and one water O atom. In the crystal, the polymeric chains are held together via inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

20.
J Mass Spectrom ; 44(5): 633-40, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19053150

RESUMO

Autoxidation of flavan-3-ols was carried out in aqueous/methanol model solutions under mildly acidic conditions (pH 6.0), and these autoxidation products were analyzed by using high performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS). The results showed that (+)-catechins and (-)-epicatechins generated autoxidation reaction with each other to form a series of oligomers that had the same [M - H](-) molecular ions (MS(1)) as those of natural procyanidins, but had completely different fragment ions (MS(2)). According to MS/MS analysis, the major fragments of these oligomers were derived not only from the retro-Diels-Alder (RDA) dissociations on the C-rings of the flavan-3-ol units, but also from the quinone-methide (QM) cleavage of the interflavan linkages (IFL), and thus they were identified as B-type dehydrodicatechins, B-type dehydrotricatechins and A-type dehydrotricatechins, respectively. The potential structures of their [M - H](-) molecular ions and partial fragment ions were deduced on the basis of the MS/MS characterization and the oxidation of flavan-3-ols in previous reports. Some specific fragment ions were found to be very useful for identifying the autoxidation oligomers (the B-type dehydrodicatechins at m/z 393, the B-type dehydrotricatechins at m/z 681 and the A-type dehydrotricatechins at m/z 725).


Assuntos
Catequina/química , Cromatografia Líquida de Alta Pressão/métodos , Modelos Químicos , Espectrometria de Massas em Tandem/métodos , Catequina/análogos & derivados , Concentração de Íons de Hidrogênio , Íons/química , Modelos Moleculares , Oxirredução
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