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91.
The adult facial nerve contains the axons from two populations of efferent neurons. First, the branchiomotor efferent neurons that innervate the muscles of the second arch. These neurons project out of the hindbrain in the motor root and form the facial motor nuclei. Second, the preganglionic efferent neurons that innervate the submandibular and pterygopalatine ganglia. These neurons project from the hindbrain via the intermediate nerve and form the superior salivatory nucleus. The motor neurons of the facial nerve are known to originate within rhombomeres 4 and 5. In the kreisler mouse mutant there is a specific disruption of the hindbrain rhombomeres 5 and 6 appear to be absent. To investigate changes in the organization of the facial motor neurons in this mutant, we have used lipophilic dyes to trace the facial motor components both retrogradely and anterogradely. As expected, facial motor neurons are missing from rhombomere 5 in this mutant. In addition, the loss of these neurons correlates with the specific loss of the superior salivatory nucleus. In contrast, the branchiomeric neurons, that originate in rhombomere 4, appear to develop normally. This includes the caudal migration of their cell bodies forming the genu of the facial nerve. Our studies confirm that rhombomeres are critical to hindbrain development and that they are the fundamental unit at which motor neurons are specified. 相似文献
92.
Vibrio cholerae O1 strains isolated mostly in Japan between 1977 and 1995 were typed according to restriction fragment patterns by cleavage of genomic DNA with Sfi I and Not I and separation by Pulsed-field gel electrophoresis (PFGE). Two hundred sixty five strains from human were divided into 60 PFGE patterns (provisional types). Strains of type 2-3, 3-4, 4-5 and 51-54 were dominant in the Philippines, Thailand, India and Indonesia, respectively. Types 1-1, 2-3, 2-53, and 3-4 were detected over a long period of time in contrast to the other types. Strains of the same type (Types 1-1, 2-3, 2-53 and others) isolated from the Japanese who had never been outside Japan were often found among strains from Southeast Asia. Most strains from humans were cholera-toxin (CT)-positive, while those from the environment and the sea were generally not. 23 strains from the environment and the sea in Japan were divided into 12 types. Strains of the same types as CT-positive strains from humans could not be found in the environment and sea. These results suggest that cholera in Japan is closely related with cholera in Southeast Asia and PFGE is useful for epidemiological analysis of cholera in Japan. 相似文献
93.
Signal processing techniques can be used to reduce linear and nonlinear distortion in high-speed lightwave systems caused by fiber dispersion and nonideal responses of optoelectronic and electronic components. The improvement in the performance of 2.5 and 10 Gb/s intensity modulation, direct detection systems is assessed for receivers which utilize an analog taped delay line equalizer to compensate for signal distortion. Synchronous and fractionally spaced equalizers are evaluated. Smart receivers that jointly optimize the decision time, decision threshold, and equalizer tap weights under a minimum bit error ration criterion are considered. This yields the optimum system performance and allows consideration of both reduced distortion and enhanced noise arising from the signal processing. The effectiveness of the equalization is determined as a function of several important system parameters. Three-tap and five-tap synchronous equalizers yield virtually the same improvement in receiver sensitivity. Depending on the system, a five-tap fractionally spaced equalizer with half-bit-period tap spacing may or may not be significantly more effective than a three-tap synchronous equalizer 相似文献
94.
95.
Ll.ltrB is a functional group II intron located within a gene (ltrB) encoding a conjugative relaxase essential for transfer of the lactococcal element pRSO1. In this work, the Ll.ltrB intron was shown to be an independent mobile element capable of inserting into an intronless allele of the ltrB gene. Ll.ltrB was not observed to insert into a deletion derivative of the ltrB gene in which the intron splice site was removed. In contrast, a second vector containing a 271-nucleotide segment of ltrB spanning the Ll.ltrB splice site was shown to be a proficient recipient of intron insertion. Efficient homing was observed in the absence of a functional host homologous recombination system. This work demonstrates that the Ll.ltrB intron is a novel site-specific mobile element in lactococci and that group II intron self-transfer is a mechanism for intron dissemination among bacteria. 相似文献
96.
RR Azar RG McKay PD Thompson JA Hirst JF Mitchell DB Fram DD Waters FJ Kiernan 《Canadian Metallurgical Quarterly》1998,32(7):1996-2002
OBJECTIVES: The purpose of this study was to compare the outcome of primary percutaneous transluminal coronary angioplasty for acute myocardial infarction (MI) when performed with or without the platelet glycoprotein IIb/IIIa antibody, abciximab. BACKGROUND: Abciximab improves the outcome of angioplasty but the effect of abciximab in primary angioplasty has not been investigated. METHODS: Data were collected from a computerized database. Follow-up was by telephone or review of outpatient or hospital readmission records. RESULTS: A total of 182 consecutive patients were included; 103 received abciximab and 79 did not. The procedural success rate was 95% in the two groups. At 30-day follow-up, the composite event rate of unstable angina, reinfarction, target vessel revascularization and death from all causes was 13.5% in the group of patients who did not receive abciximab, 4% (p < 0.05) in the abciximab group and 2.4% (p < 0.05) in the subgroup of patients (n = 87) who completed the 12-h abciximab infusion. At the end of follow-up (mean 7+/-4 months), the composite event rate was 32.4%, 17% (p < 0.05) and 13.1% (p < 0.01) in these three categories respectively. Abciximab bolus followed by a 12-h infusion was an independent predictor of event-free survival, in a Cox proportional hazards model (relative risk 0.49; 95% confidence interval 0.24 to 0.99; p < 0.05). CONCLUSIONS: Abciximab given at the time of primary angioplasty may improve the short- and medium-term outcome of patients with acute MI, especially when a 12-h infusion is completed. 相似文献
97.
98.
G McKay 《Canadian Metallurgical Quarterly》1996,5(12):13-14
Few hospitals have the in-house technology to sterilise heat and moisture sensitive reusable devices, yet the use of this type of equipment is increasing in all types of surgery. In general terms and because of limitations of existing technology, instruments and equipment have been divided into three categories based on the degree of risk of infection involved in their use: 1. Instruments and equipment which come into contact with intact skin must be cleaned before they are used. 2. Instruments and equipment which come into contact with non-sterile tissue (other than intact skin) must be disinfected before they are used. 3. Instruments and equipment which enter, or are capable of entering, the vascular system or tissue that would be sterile under normal circumstances must be sterilised before they are used. Unfortunately, some devices that should be sterilised are only disinfected in liquid chemical disinfectants. Traditional low-temperature sterilisation systems such as ethylene oxide (EtO) and low temperature steam and formaldehyde (LTSF) have many disadvantages and it is undoubtedly for this reason they have been relegated to a few specialist sterile service departments in the UK. 相似文献
99.
Gordon McKay 《American Institute of Chemical Engineers》1984,30(4):692-697
An analytical solution for a two resistance mass transfer model explaining the adsorption of Astrazone Blue dye (Basic Blue 69) onto Sorbsil silica has been developed. The model includes a film mass transfer coefficient, kf1 = 80 × 10−6cm·s−1, and an internal effective diffusivity, Deff = 18×10−9cm2·s−1 which controls the internal mass transport processes based on a pore diffusion mechanism. 相似文献
100.
Maxime Wack Ahmed Nait-Sidi-Moh Sid Lamrous Nathanael Cottin 《Artificial Intelligence and Law》2006,14(3):161-175
Legal information certification and secured storage combined with documents electronic signature are of great interest when
digital documents security and conservation are in concern. Therefore, these new and evolving technologies offer powerful
abilities, such as identification, authentication and certification. The latter contribute to increase the global security
of legal digital archives conservation and access. However, currently used cryptographic and hash coding concepts cannot intrinsically
enclose cognitive information about both the signer and the signed content. Indeed, an evolution of these technologies may
be necessary to achieve full text researches within hundreds or thousands of electronically signed documents. This article
aims at describing a possible model along with associated processes to create and make use of these new electronic signatures
called “meaningful electronic signatures” as opposed to traditional electronic signatures based on bit per bit computation. 相似文献