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81.
Tamon Yamashita Nobuhiko Kasuya Sen Nishimura Hiroshi Takeda 《Forest Ecology and Management》2004,200(1-3):215-226
Japanese cypress (Chamaecyparis obtusa Endl.) and Japanese cedar (Cryptomeria japonica D. Don) are common species for plantation forestry in Japan. Cypress is conventionally planted on sites of low fertility whereas for cedar high fertility sites are used. Objectives of this study were to compare the productivities of cypress and cedar plantations grown on adjacent sites where common properties of soils, such as pH values and C and N contents, were similar, and to relate the N cycling at their site with productivities. The stem diameter of trees, aboveground litter production and fine root biomass were measured as indices of forest productivity. Parameters of N cycling included pools of total N and mineral N (ammonium + nitrate), annual N leaching, and potentially mineralizable N. The radial stem increment of the two tree species was similar. However, cedar site had higher total basal area and annual basal increment than cypress site reflecting higher tree density on the cedar site. Aboveground litter, fine root biomass, soil organic matter, and N turnover were higher on the cedar site than on the cypress site. However, litter production and fine root biomass per unit basal area was greater at the cypress site. Phenological pattern of stem growth and periodical litter production were similar for both species during the study period (1992–2000), but showed distinct annual variations caused by the fluctuation in the ambient temperature and precipitation. Mineral N content and the N mineralization potential were greater on the cedar site, indicating greater N availability and higher total tree productivity at the cedar site than those at the cypress site. When provided with more space in the canopy to expand more needles and in the soil to develop more fine roots to exploit sufficient resources, the individual cypress trees have the potential to grow faster. On fertile site and at lower tree density, thicker logs of cypress might be yielded. 相似文献
82.
Nakagawa K Kubota H Kimura T Yamashita S Tsuzuki T Oikawa S Miyazawa T 《Journal of agricultural and food chemistry》2007,55(22):8928-8933
1-deoxynojirimycin (DNJ), a potent glucosidase inhibitor, is a characteristic constituent of the mulberry leaf. Dietary mulberry DNJ may be beneficial for the suppression of abnormally high blood glucose levels, thereby preventing diabetes mellitus. Although there is considerable interest in the effects of mulberry DNJ, the intestinal absorption and pharmacokinetic profile of orally administered mulberry DNJ have never been characterized. In this study, we developed a method for determining the level of plasma DNJ by hydrophilic interaction chromatography coupled to a mass spectrometric detector (HILIC-MS) to investigate the absorption and metabolism of orally administered mulberry DNJ in rats. DNJ was separated from plasma extract on a TSK gel Amide-80 column, a representative column for HILIC. At postcolumn, DNJ was concurrently detected and identified by MS. The plasma DNJ concentration in fasted rats was below the detection limit [<1 microg (6 nmol)/mL]; however, the concentration reached a maximum [15 microg (92 nmol)/mL] 30 min after the administration of mulberry DNJ (110 mg/kg of body weight), and the DNJ concentration decreased rapidly thereafter. When the rats received different amounts of mulberry DNJ (1.1, 11, and 110 mg/kg of body weight), dose-dependent incorporation of DNJ into the plasma was confirmed. We did not detect any DNJ metabolites in the plasma. These findings indicate that orally administered mulberry DNJ is absorbed as an intact form from the alimentary tract and then is quickly excreted from the body. The developed HILIC-MS method could be applied in determining levels of DNJ in urine and tissues, and therefore, the method would be a powerful tool for studying the metabolic fate of mulberry DNJ as well as its bioavailability. 相似文献
83.
Yamashiro H Kumamoto K Wang H Yamashita Y Terada T 《The Journal of reproduction and development》2006,52(3):397-406
The objective of this experiment was to investigate whether the motility parameters and acrosome integrity of goat ejaculated spermatozoa are affected by collecting semen into tubes containing an extender, and thereby determine the significance of reducing contact between seminal plasma and the sperm membrane at ejaculation. Semen were collected from three goats into tubes containing 0, 1 or 10 ml extender, or collected into tubes containing 10 ml extender supplemented with 0.1, 1 or 5% BSA. Sperm motion parameters were evaluated immediately after collection, after washing, and during a 3-h thermal resistance test. Acrosome integrity was assessed using FITC-PNA staining. Semen collection into tubes containing 10 ml extender produced higher sperm motility, progressive motility, and acrosome integrity than that using a smaller volume of extender. Furthermore, collection into 5% BSA-containing extender exhibited higher sperm characteristics and maintained high sperm motility and progressive motility throughout incubation. In conclusion, semen collection into tubes with a large volume of extender, especially extender containing higher concentrations of BSA, improved the quality of ejaculated spermatozoa, strongly suggesting that the in vitro functional characteristics of the spermatozoa were abruptly modified by flash sperm contact with accessory sex gland fluid at ejaculation. 相似文献
84.
Nucleophilic, anionic boryl compounds are long-sought but elusive species. We report that reductive cleavage of the boron-bromine bond in N,N'-bis(2,6-diisopropylphenyl)-2-bromo-2,3-dihydro-1H-1,3,2-diazaborole by lithium naphthalenide afforded the corresponding boryllithium, which is isoelectronic with an N-heterocyclic carbene. The structure of the boryllithium determined by x-ray crystallography was consistent with sp(2) boron hybridization and revealed a boron-lithium bond length of 2.291 +/- 0.006 angstroms. The structural similarity between this compound and the calculated free boryl anion suggests that the boron atom has an anionic charge. The (11)B nuclear magnetic resonance spectrum also supports the boryl anion character. Moreover, the compound behaves as an efficient base and nucleophile in its reactions with electrophiles such as water, methyl trifluoromethanesulfonate, 1-chlorobutane, and benzaldehyde. 相似文献
85.
Kitadai N Obi T Yamashita S Murase T Takase K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(3):395-397
Susceptibility to 13 antimicrobial agents was examined for 138 Escherichia coli isolates obtained from 192 fecal samples of wild cranes that migrated for wintering to the Izumi plain, Kagoshima prefecture in Japan. The numbers of isolates that were resistant to the antimicrobials used in this study are as follows: oxytetracycline (OTC), 22 isolates; minocycline, 7 isolates; ampicillin (ABPC), 4 isolates; nalidixic acid, 4 isolates; enrofloxacin, 2 isolates; kanamycin, one isolate. Multidrug resistant isolates exhibiting 2-4 drug resistances were obtained. All of the OTC-resistant isolates carried either the tet (A) or tet(B) gene. The bla(TEM) gene was found in all of the ABPC-resistant isolates. 相似文献
86.
Yamashita K Furukawa E Itami T Ishizuka T Tamura J Miyoshi K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(4):507-511
It is well known that heart rate or arterial blood pressure may increase in response to surgical stimulation despite the absence of a purposeful movement. However, there is limited information regarding anesthetic requirement for blunting adrenergic response in dogs. This study was designed to compare the minimum alveolar concentrations of sevoflurane required to prevent autonomic response (MAC-BAR) and purposeful movement (MAC) in dogs. Sevoflurane MAC-BAR and MAC were determined in 5 beagle dogs by judging dogs' response to a noxious electrical stimulus applied to the gingiva. The sevoflurane MAC-BAR was significantly higher than MAC (3.33 ± 0.48 vs 2.10 ± 0.28%, P=0.005). These results suggested that autonomic responses occurred at sevoflurane anesthetic concentrations at which purposeful movements were absent. 相似文献
87.
T Kushiro K Yamashita MA Umar Y Izumisawa K Taguchi WW Muir 《Veterinary anaesthesia and analgesia》2005,32(4):19-19
MKM–OS anesthesia provides general anesthesia with minimum cardiovascular depression in experimental horses. The purpose of this study was to evaluate the effect of MKM–OS anesthesia in clinical cases. Sixty‐eight horses were anesthetized with MKM–OS anesthesia for selective or emergency surgery. The horse physical status was categorized based upon the American Society of Anesthesiologists (ASA) classification scheme. Forty‐four horses were classified as ASA I or II (low‐risk; 30 soft tissue, eight ophthalmic, and six orthopedic surgeries) and 24 horses were classified as ASA III to V (high‐risk; 24 emergency colic surgeries). All horses were administered medetomidine (0.005 mg kg–1 IV) as premedication and anesthetized with ketamine (2.5 mg kg–1 IV) and midazolam (0.04 mg kg–1 IV). The horses were orotracheally intubated and connected to a large animal breathing circuit that delivered oxygen‐sevoflurane and administered the midazolam (0.8 mg mL–1)‐ketamine (40 mg mL–1)‐medetomidine (0.05 mg mL–1) drug combination at a rate of 0.025 mL kg–1 hour–1. Surgical anesthesia was maintained by controlling the dial setting of the sevoflurane vaporizer and achieved by delivering 1.6–1.8% of end‐tidal sevoflurane concentration. All horses were mechanically ventilated during anesthesia. Hypercapnia and hypoxia were not sufficiently improved in high‐risk horses (PaCO2; low‐risk 45–53 mm Hg versus high‐risk 56–60 mm Hg, p < 0.01: PaO2 low‐risk 248–388 mm Hg versus high‐risk 95–180 mm Hg, p < 0.01). Heart rate was significantly higher in high‐risk horses (low‐risk 37–42 bpm versus high‐risk 44–73 bpm, p < 0.01). Dobutamine infusion was required in five low‐risk (11%) and 17 high‐risk horses (68%) to maintain mean arterial blood pressure >70 mm Hg. Eleven high‐risk horses died during the perioperative period (three euthanized during surgery, two died during recovery, six died after recovery). The quality of recovery was good in low‐risk horses and good to satisfactory in high‐risk horses. MKM–OS anesthesia provided excellent surgical anesthesia with minimal to mild cardiovascular depression in low risk‐horses and mild to moderate cardiovascular depression in high risk‐horses. The possibility of preserve cardiovascular function could be the advantage of MKM–OS anesthesia in high‐risk horses. 相似文献
88.
Yamashita K Muir WW Tsubakishita S Abrahamsen E Lerch P Izumisawa Y Kotani T 《Journal of the American Veterinary Medical Association》2002,221(8):1150-1155
OBJECTIVE: To evaluate effects of infusion of guaifenesin, ketamine, and medetomidine in combination with inhalation of sevoflurane versus inhalation of sevoflurane alone for anesthesia of horses. DESIGN: Randomized clinical trial. ANIMALS: 40 horses. PROCEDURE: Horses were premedicated with xylazine and anesthetized with diazepam and ketamine. Anesthesia was maintained by infusion of guaifenesin, ketamine, and medetomidine and inhalation of sevoflurane (20 horses) or by inhalation of sevoflurane (20 horses). A surgical plane of anesthesia was maintained by controlling the inhaled concentration of sevoflurane. Sodium pentothal was administered as necessary to prevent movement in response to surgical stimulation. Hypotension was treated with dobutamine; hypoxemia and hypercarbia were treated with intermittent positive-pressure ventilation. The quality of anesthetic induction, maintenance, and recovery and the quality of the transition to inhalation anesthesia were scored. RESULTS: The delivered concentration of sevoflurane (ie, the vaporizer dial setting) was significantly lower and the quality of transition to inhalation anesthesia and of anesthetic maintenance were significantly better in horses that received the guaifenesin-ketamine-medetomidine infusion than in horses that did not. Five horses, all of which received sevoflurane alone, required administration of pentothal. Recovery time and quality of recovery were not significantly different between groups, but horses that received the guaifenesin-ketamine-medetomidine infusion required fewer attempts to stand. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in horses, the combination of a guaifenesin-ketamine-medetomidine infusion and inhalation of sevoflurane resulted in better transition and maintenance phases while improving cardiovascular function and reducing the number of attempts needed to stand after the completion of anesthesia, compared with inhalation of sevoflurane. 相似文献
89.
Wakita Y Shimizu A Hájek V Kawano J Yamashita K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(3):237-243
Staphylococcus intermedius from pigeons, dogs, foxes, mink, and horses, was characterized by pulsed-field gel electrophoresis (PFGE) to evaluate the use of this typing method for discriminating among strains. SmaI cut the chromosomal DNA into 7-13 fragments ranging from approximately 48 kb to 655 kb, with most of the detectable fragments being smaller than 172 kb. S. intermedius from various animals had a high degree of restriction fragment length polymorphism. Pigeon strains have a similar genotype, despite the difference in their isolation area. Phage typing indicated that the dog, fox, and mink strains belong to the canine I or canine II type. The PFGE method further differentiated the mink strains from the dog and fox strains with regard to three fragments between 256 kb and 570 kb. As such, genomic DNA fingerprinting by PFGE appears to be an effective technique for discriminating S. intermedius strains from various animals. A combination of PFGE typing and phage typing would provide more detailed information than the single method for ecological investigations of S. intermedius. 相似文献
90.
Yamashita K Fujiwara C Azuma R Sawazaki T Nakao Y Hasegawa A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(8):673-676
Housedust mites, Dermatophagoides pteronyssinus (D. pteronyssinus) and Dermatophagoides farinae (D. farinae), are the important causative agents of allergic diseases in human and animals. By using 165 dogs suffering from atopic dermatitis (AD), serum levels of immunogloblin E (IgE) antibody against 25 kinds of allergen including housedust mites were determined. Housedust mites were the most frequent allergen against which 90 of the 165 allergic dogs (54.5%) by IMMUNODOT assay. With the further analysis of immunoblotting assay in the 90 dogs sensitized with housedust mites, antigenic proteins of housedust mites recognized by IgE antibodies were with the apparent molecular masses of 15, 76, 90, 98, and 170-kD. Among them, the 15-kD protein that might be identical to Group 2 antigens (Der f2, Der p2) was prominently observed (52/90). This study indicates that about a half of dogs with AD were sensitized to housedust mites, suggesting that Group 2 antigens of housedust mites may be a major allergen in canine AD. 相似文献