共查询到20条相似文献,搜索用时 15 毫秒
1.
STATISTICAL ASPECTS OF THE INDEPENDENT JOINT ACTION OF POISONS, PARTICULARLY INSECTICIDES 总被引:1,自引:0,他引:1
Methods are described for discovering whether a mixture of two poisons is as toxic as predicted on the hypothesis of independent joint action. These include X2 tests and a procedure for finding the maximum likelihood estimate of the coefficient of correlation in resistance to the poisons. The methods are illustrated using data from insecticidal tests.
In the insecticidal tests, flour beetles, Tribolium castaneum Herbst, were sprayed with, or exposed to films of, different insecticides in solution in Shell oil P 31. The insecticides were pyrethrins, D.D.T., and B.H.C., singly and in pairs. The statistical analysis of the results showed that pyrethrins and D.D.T. could have acted independently both as films and as direct sprays; D.D.T. and B.H.C. could have acted independently as films but not as direct sprays; and B.H.C. and pyrethrins could not have acted independently either as films or as direct sprays.
These findings are discussed, and it is concluded that independent action should be regarded as a special case of a more general type of joint action for which the term dissimilar is proposed. A general method of approach is suggested for the conception and development of hypotheses of the joint action of poisons. 相似文献
In the insecticidal tests, flour beetles, Tribolium castaneum Herbst, were sprayed with, or exposed to films of, different insecticides in solution in Shell oil P 31. The insecticides were pyrethrins, D.D.T., and B.H.C., singly and in pairs. The statistical analysis of the results showed that pyrethrins and D.D.T. could have acted independently both as films and as direct sprays; D.D.T. and B.H.C. could have acted independently as films but not as direct sprays; and B.H.C. and pyrethrins could not have acted independently either as films or as direct sprays.
These findings are discussed, and it is concluded that independent action should be regarded as a special case of a more general type of joint action for which the term dissimilar is proposed. A general method of approach is suggested for the conception and development of hypotheses of the joint action of poisons. 相似文献
2.
Frederic W. Ilfeld 《The Western journal of medicine》1953,78(2):118-120
Hemiarthroplasty of the hip is a simplification of the Smith-Petersen cup arthroplasty in which half of the joint or femoral head is reshaped to fit the vitallium cup. This procedure shortens hospitalization to 10 to 14 days and has been successful in the relief of hip pain and in increasing hip motions. It is indicated when the disease is localized for the most part to the femoral head. 相似文献
3.
罗宗涵 《上海生物医学工程》1996,17(1):26-29
全臂假肢肩关节结构,不但要符合人手臂的外形特征,而且在结构设计的布局上还要考虑仿生性和造型的美观逼真。由于在肩关节处要承受相当大的力矩,肩关节机构要经得起前臂的较大负载外力,所以功能可靠更为重要。因此关肩节机构的 设计具有相当的难度。本机构利用蜗轮蜗杆传动的优点,来实现肩关节前屈后伸运动。克服了链传间隙大的缺点,缩短了力臂改善了肩关节处的受力状态,并且在假肢的上臂安装了上臂手动旋转环,其既可在任意 相似文献
4.
John C. Ruddock 《The Western journal of medicine》1949,71(2):110-116
Peritoneoscopic examination has now been accepted throughout the world as a safe diagnostic procedure in lieu of laparotomy in selected cases.Laparotomies for diagnostic purposes alone should be condemned.Peritoneoscopy should not be done without a definite purpose and the procedure should not be expected to accomplish more than the purpose for which it is done. Indications for the procedure are set forth in detail. Experience has established definite contraindications, which are reviewed.The procedure is especially indicated for patients who are aged, emaciated, anemic, or poor surgical risks for any reason.All patients having ascites of undetermined cause should be examined by peritoneoscopy.The method is especially indicated for examination of patients with liver disease of all types, for pelvic examinations, for use to determine existence of ectopic pregnancy, and for tumor localization.Considerable use was made of the procedure during World War II to determine the extent and site of intra-abdominal injuries caused by crushing, explosions, and falls from high places.The procedure permits early and correct diagnosis, early decision as to the advisability of operation, and determination as to operability in cases of malignant gastric lesions. It is a safe method for obtaining biopsy specimens from intra-abdominal tissue and organs.Accuracy of diagnosis in cases in which the method can be used is considerably greater with peritoneoscopic examination than with clinical information alone. 相似文献
5.
鲤形目鱼类咽齿形态及发育的比较研究 总被引:8,自引:0,他引:8
对鲤形目所属6科类的咽龄形态及个体发育模型进行了较详细的比较研究。结果得出除双孔鱼科鱼类未形成咽齿外,其它5科鱼类在咽齿发生的过程中具有齿着生方向完全相反的两种发育模式。以亚口鱼科,鳅科和平鳍鳅为一类的齿后向增长的类型和以鲤科另一类的齿同增长的类型。 相似文献
6.
P. J. K. BURTON 《Ibis》1978,120(2):171-177
The Harrier-Hawks Polyboroides spp. and Crane Hawk Geranospiza caerulescens have legs capable of flexing backward as well as forward at the intertarsal joint. This is evidently adaptive to their habit of extracting prey from crevices using the feet. The structure and properties of the intertarsal joint have been investigated using an alcoholic specimen of P. typus and skeletons of P. typus and G. caerulescens; specimens of Circus cayaneus (alcoholic) and C. aeruginosus (skeleton) were used for comparison. Increased mobility of the joint extends to medial-lateral swing as well as flexion; the faculty for backward flexion appears to be somewhat offset by some loss of forward flexion. The tibiotarsus, tarsometatarsus and the ligaments and menisci of the intertarsal joint are described and figured. No significant differences in musculature were found. The most obvious difference between Circus on the one hand, and Polyboroides and Geranospiza on the other is the extreme narrowness of the joint in the latter two genera. This is probably the most important factor permitting increased joint mobility. The possible significance of other structural features observed is also discussed, and related adaptations of the distal tarsometatarsus and foot are pointed out. It is concluded that the resemblances of the hind limbs of these two genera are not strong evidence of phylogenetic relationship. 相似文献
7.
Paul M. Meadows 《The Western journal of medicine》1964,100(2):85-87
Brain scanning by means of externally placed moving scintillation detectors has proven to be an easy accurate method for demonstrating size, shape and position of many types of brain tumors. In a series of 53, there were few false negatives and few false positives. The procedure is easy on the patient, does not require anesthesia and can be done on outpatients. It is recommended as a screening procedure for all brain tumor suspects. 相似文献
8.
S. S. Maxwell 《The Journal of general physiology》1919,2(2):123-132
1. A dogfish from which all six ampullæ have been removed maintains its equilibrium; the righting reactions occur promptly; compensatory movements of the eyes occur in response to rotations in all planes except the horizontal; the compensatory position of the eyes is retained if the animal is held in an abnormal position. Both the static and dynamic functions of equilibrium continue, therefore, after complete removal of all the semicircular canals and all the ampullæ. 2. After complete removal of the otoliths from the vestibules without injury to the ampullæ the animal maintains its equilibrium in the water, rights itself promptly, and makes compensatory motions to rotations in all planes. If held in an abnormal position the compensatory position of the eyes is maintained. Both static and dynamic functions of equilibrium continue. 3. Destruction of both the semicircular canals and the otolith organs completely abolishes all compensatory movements and equilibrium reactions of labyrinthine origin. 4. It is pointed out that these observations do not justify the theory of Mach and Breuer that the ampullæ and semicircular canals are the organs for the dynamic functions of equilibrium, and that the otoliths are the organs for the static functions of equilibrium. 5. The new experiments recorded in this paper show that the ampullæ alone (without the otoliths) suffice for all the dynamic and all the static functions of equilibrium of the ear; and that the otolith organs (without the ampullæ) suffice for all the static and for all the dynamic functions of equilibrium of the ear with the exception of the response to a rotation of the animal in a horizontal plane. 相似文献
9.
An apparatus and a procedure are described to measure the critical frequency of flicker using different portions of the eye. The observer, looking through a pupil of fixed dimensions, views a field of 2° whose illumination is periodically interrupted and which is surrounded by a field of 10° whose illumination is continuous but otherwise identical with the interrupted field. Various parts of the apparatus are concerned with controlling and recording the retinal position of the field, its intensity, its spectral composition, and the frequency of interruption of its illumination. The procedure is so simplified and regulated that a complete set of readings over the whole intensity range of vision can be made at one sitting without fatigue or strain. 相似文献
10.
Double contrast arthrography, a method in which a dye and then oxygen is injected, can be used to visualize pathologic changes in the knee joint, that otherwise cannot be recognized preoperatively. In 28 cases in which the procedure was carried out there was no evidence of damage owing to it.This method is worthy of consideration for visualization of conditions in the shoulder joint, hip, or any joint having a distensible cavity. 相似文献
11.
A STUDY OF THE DIFFUSIBLE FACTOR RELEASED BY THE JELLY OF THE EGG OF THE TOAD, BUFO ARENARUM 总被引:2,自引:2,他引:0
Some properties of an essential factor for fertilization released from the oocyte strings of the toad, Bufo arenarum were studied. All the experiments were carried out with a partially purified preparation of this diffusible factor, and the general procedure consisted in assaying under different conditions its capacity to recover the fertilizability of oocytes previously deprived of this active substance. Using this procedure, a test was devised for estimating the diffusible factor activity.
As regards the mechanism of action of this fertilization factor the data reported here are not consistent with the previous assumption that the factor plays its role in fertilization through a simple pH rise of the inseminating medium.
Treatment of the gametes with the diffusible factor before insemination proved to be ineffective to promote fertilization; the factor must be present at the very moment of insemination. 相似文献
As regards the mechanism of action of this fertilization factor the data reported here are not consistent with the previous assumption that the factor plays its role in fertilization through a simple pH rise of the inseminating medium.
Treatment of the gametes with the diffusible factor before insemination proved to be ineffective to promote fertilization; the factor must be present at the very moment of insemination. 相似文献
12.
在免疫组化染色过程中,如何把各组织中的相关抗原充分地显示出来,许多免疫组化工作者进行了各种方法的探讨。但是,其结果却不十分理想,主要问题是染色的背景深及组织切片容易脱离载片,造成染色的失败。真空负压在免疫组化染色过程中的应用,能减少步骤,缩短时间,消除非特异性染色,使背景清晰,易于判断结果。并且避免了组织切片脱落现象,还可提高某些抗体的稀释度。此法均可使用金属性或非金属性器皿,而且整个过程都可在室温中进行,比微波技术更为简便易行,安全可靠,实用性强,成本低,有较大的推广价值。 相似文献
13.
V. A. Safronov 《Human physiology》2005,31(6):724-727
A procedure for investigating the patellar reflex is described for isometric conditions when the position of the shin relative to the thigh is rigidly fixed by a special device. The sensors of the device record the development of the moment of force in each knee joint separately. The results obtained with an electromyogram and a mechanogram are compared. 相似文献
14.
滇桐属系统位置的分支分析 总被引:2,自引:0,他引:2
本文以讨论系统位置有争议的滇桐属的归属问题,尝试在植物分类学中具体应用分支系统学原理和方法的可能性。作者认为近年来分支系统学中出现的一种倾向,即不再强调祖先和直接的谱系关系,而把分支图解仅仅作为一种归类手段,为本文提供了理论基础。通过对梧桐科和椴树科7个属15个性状状态的分支分析,建立了符合简约性原则的分支图解。分支图解表明,滇桐属与通常置于梧桐科的马克韦桐属具有较密切的关系,而它们与椴树科的关系比与梧桐科的关系更接近。结论支持把滇桐属作为椴树科成员的观点。 相似文献
15.
Robert S. Pollack 《The Western journal of medicine》1955,82(6):444-446
Some melanomas arise from compound and junctional nevi. Since there is a relatively high incidence of malignant diseases on the soles of the feet and the genitalia, routine removal of nevi developing in those areas is recommended.“Juvenile melanomas” are active, cellular nevi occurring in prepubertal children. The clinical course is probably benign.The tenet of excision and dissection in continuity where feasible of the primary melanoma and the regional lymph nodes is reemphasized. When continuous dissection is not possible, regional node dissection is recommended as a separate procedure.Major amputations for melanomas of the extremities are not recommended for the usual case. 相似文献
16.
P Joshi A. Evans D. N. Rana R. Hale G. E. Wilson M. Desai & S. M. Ismail 《Cytopathology》2006,17(S1):21-22
Introduction: Current protocols for staging gynaecological cancers include cytopathological examination of peritoneal washings taken at the time of definitive surgery. We investigated the clinical usefulness of this procedure.
Methods: During 2004 and 2005, 140 peritoneal washings were submitted for cytopathological examination in our institutions for staging of 36 ovarian, 101 endometrial and 3 synchronous ovarian/endometrial cancers.
Results: The washings contained malignant cells in 39 cases (28%). 35 of these cases had high stage disease – not confined to the organ of origin (i.e. stage 2 or more for ovary and stage 3 or more for endometrial). The other 4 were stage 1C ovarian cancers where there was either rupture or tumour involvement of the capsule. In only 2 of the 39 positive cases the cancer was marginally upstaged by the positive washings – these were ovarian cancers upstaged from 2A /B to 2C.
Discussion: These findings suggest that peritoneal washing cytology as a routine procedure for staging ovarian and endometrial cancer is of limited clinical value. A larger study is needed to determine whether this procedure should continue to be included in staging protocols for gynaecological cancer. 相似文献
Methods: During 2004 and 2005, 140 peritoneal washings were submitted for cytopathological examination in our institutions for staging of 36 ovarian, 101 endometrial and 3 synchronous ovarian/endometrial cancers.
Results: The washings contained malignant cells in 39 cases (28%). 35 of these cases had high stage disease – not confined to the organ of origin (i.e. stage 2 or more for ovary and stage 3 or more for endometrial). The other 4 were stage 1C ovarian cancers where there was either rupture or tumour involvement of the capsule. In only 2 of the 39 positive cases the cancer was marginally upstaged by the positive washings – these were ovarian cancers upstaged from 2A /B to 2C.
Discussion: These findings suggest that peritoneal washing cytology as a routine procedure for staging ovarian and endometrial cancer is of limited clinical value. A larger study is needed to determine whether this procedure should continue to be included in staging protocols for gynaecological cancer. 相似文献
17.
S. L. Perzik 《The Western journal of medicine》1951,74(5):374-376
Cancer involving the antrum can be cured in a greater percentage of cases if the lesions are detected earlier, specifically diagnosed histologically, and radically managed at the time of the initial treatment. The procedure of choice is, first, surgical removal (with a scalpel) of as much of the tumor as is possible without risk of operative death, then limited but specific cancerocidal radiation as indicated by operative findings or regular postoperative observation. The period of convalescence will be less distressing and shorter with this procedure than with others; and, in those cases in which cure is not effected, palliation will be more satisfactory. The cured patients are cosmetically acceptable without functional disability except for unilateral loss of vision in cases in which exenteration of the orbit is necessary. 相似文献
18.
19.
20.
TSUYOSHI SAWAI 《Development, growth & differentiation》1976,18(4):357-361
Sawai (2) found in the amphibian egg that furrow-inducing cytoplasmic component (FIC) was localized along the cleavage furrow, which could induce a furrow on the polar surface of cleaving egg under which FIC was injected. But this procedure failed on the surface of uncleaved fertilized egg. In the present experiments, an attempt was made to induce a cleavage furrow on the surface of uncleaved egg of the newt, Cynops pyrrhogaster. A piece of the cortex was cut from the uncleaved egg, which was transplanted to the egg just before or just after the onset of the cleavage, using a fine glass needle. After the transplantation FIC was injected beneath the graft with a capillary. The graft reacted to FIC and a furrow-like dent was induced at the position. Besides, stiffness of the graft increased during the cleavage of the host egg. In contrast to the cortical grafting, a large amount of the cytoplasm excluding FIC was injected under the cortex of an uncleaved egg. After several minutes FIC was deposited at the site. A furrow-like dent was formed there in many cases. 相似文献