全文获取类型
收费全文 | 6806篇 |
免费 | 380篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 288篇 |
妇产科学 | 169篇 |
基础医学 | 1061篇 |
口腔科学 | 95篇 |
临床医学 | 463篇 |
内科学 | 1269篇 |
皮肤病学 | 206篇 |
神经病学 | 643篇 |
特种医学 | 432篇 |
外国民族医学 | 5篇 |
外科学 | 858篇 |
综合类 | 47篇 |
预防医学 | 306篇 |
眼科学 | 181篇 |
药学 | 453篇 |
中国医学 | 2篇 |
肿瘤学 | 697篇 |
出版年
2023年 | 38篇 |
2022年 | 75篇 |
2021年 | 88篇 |
2020年 | 66篇 |
2019年 | 78篇 |
2018年 | 111篇 |
2017年 | 86篇 |
2016年 | 118篇 |
2015年 | 137篇 |
2014年 | 178篇 |
2013年 | 216篇 |
2012年 | 283篇 |
2011年 | 308篇 |
2010年 | 189篇 |
2009年 | 207篇 |
2008年 | 315篇 |
2007年 | 257篇 |
2006年 | 284篇 |
2005年 | 296篇 |
2004年 | 255篇 |
2003年 | 267篇 |
2002年 | 221篇 |
2001年 | 236篇 |
2000年 | 213篇 |
1999年 | 193篇 |
1998年 | 128篇 |
1997年 | 133篇 |
1996年 | 106篇 |
1995年 | 72篇 |
1994年 | 99篇 |
1993年 | 87篇 |
1992年 | 112篇 |
1991年 | 99篇 |
1990年 | 94篇 |
1989年 | 113篇 |
1988年 | 129篇 |
1987年 | 110篇 |
1986年 | 99篇 |
1985年 | 82篇 |
1984年 | 56篇 |
1983年 | 60篇 |
1982年 | 49篇 |
1981年 | 47篇 |
1980年 | 48篇 |
1979年 | 55篇 |
1978年 | 38篇 |
1977年 | 40篇 |
1975年 | 48篇 |
1974年 | 41篇 |
1966年 | 46篇 |
排序方式: 共有7213条查询结果,搜索用时 33 毫秒
91.
Stapf C Hartmann A Hofmeister C Schumacher HC Marx P Mast H 《Fortschritte der Neurologie-Psychiatrie》1999,67(11):509-523
Pure word deafness (auditory verbal agnosia) is characterized by an impairment of auditory comprehension, repetition of verbal material and writing to dictation whereas spontaneous speech production and reading largely remain unaffected. Sometimes, this syndrome is preceded by complete deafness (cortical deafness) of varying duration. Perception of vowels and suprasegmental features of verbal utterances (e.g., intonation contours) seems to be less disrupted than the processing of consonants and, therefore, might mediate residual auditory functions. Often, lip reading and/or slowing of speaking rate allow within some limits to compensate for speech comprehension deficits. Apart from a few exceptions, the available reports of pure word deafness documented a bilateral temporal lesion. In these instances, as a rule, identification of nonverbal (environmental) sounds, perception of music, temporal resolution of sequential auditory cues and/or spatial localization of acoustic events were compromised as well. The observed variable constellation of auditory signs and symptoms in central hearing disorders following bilateral temporal disorders, most probably, reflects the multitude of functional maps at the level of the auditory cortices subserving, as documented in a variety of non-human species, the encoding of specific stimulus parameters each. Thus, verbal/nonverbal auditory agnosia may be considered a paradigm of distorted "auditory scene analysis" (Bregman 1990) affecting both primitive and schema-based perceptual processes. It cannot be excluded, however, that disconnection of the Wernicke-area from auditory input (Geschwind 1965) and/or an impairment of suggested "phonetic module" (Liberman 1996) contribute to the observed deficits as well. Conceivably, these latter mechanisms underly the rare cases of pure word deafness following a lesion restricted to the dominant hemisphere. Only few instances of a rather isolated disruption of the discrimination/identification of nonverbal sound sources, in the presence of uncompromised speech comprehension, have been reported so far (nonverbal auditory agnosia). As a rule, unilateral right-sided damage has been found to be the relevant lesion. 相似文献
92.
Weissbach L Bussar-Maatz R Löhrs U Schubert GE Mann K Hartmann M Dieckmann KP Fassbinder J 《European urology》1999,36(6):601-608
OBJECTIVE: In a prospective multicenter trial, it was our intention to elucidate clinical prognostic factors of seminomas with special reference to the importance of human chorionic gonadotropin (HCG) elevations in histologically pure seminomas. METHODS: Together with 96 participating urological departments in Germany, Austria, and Switzerland, we recruited 803 seminoma patients between 1986 and 1991. Out of 726 evaluable cases, 378 had elevated, while 348 had normal HCG values in the cubital vein. Histology was reviewed by two reference pathologists. HCG levels were determined in local laboratories and in a study laboratory. Standard therapy was defined as radiotherapy in stages I (30 Gy) and IIA/B (36 Gy) to the paraaortal and the ispilateral (stage I) and bilateral (stage IIA/B) iliac lymph nodes; higher stages received polychemotherapy and surgery in case of residual tumor masses. Statistics included chi-square tests, linear Cox regression, and log-rank test. RESULTS: The HCG elevation is associated with a larger tumor mass (primary tumor and/or metastases). HCG-positive and HCG-negative seminomas had no different prognostic outcome after standard therapy. The overall relapse rate of 6% and the survival rate of 98% after 36 months (median) indicate an excellent prognosis. The calculation of the relative risk of developing a relapse discovered only stage of the disease and elevation of the lactate dehydrogenase concentration and its prolonged marker decay as independent prognostic factors for seminomas. A more detailed analysis of the prognostic significance of the stage revealed that the high relapse rate in stage IIB seminomas after radiotherapy (24%) is responsible for this result. CONCLUSIONS: We conclude that HCG-positive seminomas do not represent a special entity. Provided standard therapy is applied, HCG has no influence on the prognosis. Patients with stage IIB disease should be treated with chemotherapy because of the demonstrated higher relapse rate outside the retroperitoneum. 相似文献
93.
STUDY DESIGN: An investigation of the efficacy of an individually scheduled, risk factor-based cognitive behavioral therapy and a standardized electromyographic biofeedback intervention in the prevention of chronicity in patients with acute sciatica and psychosocial risk factors for chronicity. OBJECTIVES: To investigate the possibility of enhancing pain relief and preventing chronicity in patients with acute sciatica, based on a screening for psychosocial high-risk factors of chronification. SUMMARY OF BACKGROUND DATA: Psychological interventions were evaluated mainly in patients with chronic low back pain. Numerous randomized trials have demonstrated their efficacy, whereas the amount of pain relief was found to be marginal. METHODS: Subjective and behavioral outcome parameters were compared with the respective parameters in age-, gender-, and diagnosis-matched high- and low-risk patients. No additional behavioral treatment for in-patient medical therapy was offered to the patients. Outcome of these patients also was compared with that of a group of refusers of behavioral therapy. Psychological, functional, and behavioral variables were measured before and after treatment and at 3-, 6-, 12- and 18-month follow-up visits. Changes over time, group differences, and possible group x time interactions were analyzed by analysis of variance and nonparameteric comparisons. RESULTS: Data analysis showed a statistically and clinically significant, beneficial effect of both behavioral interventions. However, risk factor-based cognitive behavioral therapy was superior to electromyographic biofeedback intervention with respect to pain relief and application for early retirement. The cognitive behavioral therapy showed a similar good outcome (e.g., 90% showed a clinical significant pain reduction) as the low-risk patients (83% pain reduction). High risk patients and refusers of therapy showed a poor outcome in pain (33% and 20% pain reduction, respectively), disability, and work performance. CONCLUSIONS: Individually scheduled, risk factor-based cognitive behavior therapy could be a beneficial treatment modality, which can be offered, in addition to a medical treatment, to patients with acute sciatica and psychosocial high risk factors for chronicity. It may be an effective way to prevent chronification in these patients. 相似文献
94.
OBJECTIVE: To evaluate the efficacy and safety of intracameral lidocaine in cataract surgery compared to peribulbar anesthesia. DESIGN: A prospective, randomized, controlled study. PARTICIPANTS: A total of 200 consecutive cataract patients (200 eyes) participated. INTERVENTION: Eyes were randomly assigned to two groups: one group received 0.15 ml intracameral 1% unpreserved lidocaine combined with topical anesthesia (oxybuprocaine); the other group received 6 ml prilocaine peribulbar before phacoemulsification with sclerocorneal tunnel incision. MAIN OUTCOME MEASURES: Duration of surgery was measured; implicit time and amplitudes of the b-waves of the photopic electroretinogram (ERG) potentials (single-flash ERG and the 30-Hz flicker ERG) were recorded; frequencies of intraoperative problems, complications, intraoperative, and postoperative pain were evaluated. RESULTS: After lidocaine anesthesia combined with topical anesthesia, similar complications were found, longer operation time (P < 0.001), and significantly better visual acuity immediately after surgery (P < 0.001). The ERG amplitudes were not significantly reduced after 0.15-ml intracameral lidocaine half an hour after surgery (P > 0.05). CONCLUSION: Intracameral lidocaine 1% combined with topical anesthesia can be recommended as an alternative procedure to peribulbar anesthesia in cataract surgery with corneoscleral tunnel incision. 相似文献
95.
Norbert Anders Karl-Titus Hoffmann Norbert Hosten Tony Walkow Roland Felix Christian Hartmann 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》1999,96(10):658-662
Dacryocystorhinostomy is still the standard procedure complete stenosis of the nasolacrimal duct. New methods try to preserve the natural lacrimal pathway. Song implanted in 1995 a nasolacrimal polyurethane stent through the nasolacrimal duct. The results and complications of this new method are described in this prospective study. METHODS: Thirty consecutive patients with complete obstruction of the nasolacrimal duct or lacrimal sac were included in the study. The stenosis was localized by dacryocystography. The ages ranged from 22 to 87 years (mean, 58.9 +/- 16 years). Dacryocystography was performed immediately, 4 weeks and 8 months after the procedure to verify the position and patency of the stent. RESULTS: Twenty-five short (35 mm) and 5 long (45 mm) stents were implanted. Twenty-four of 30 patients after 4 weeks and 9 of 10 patients after 8 months had reduced or no complaints. In 1 patient the stent was obstructed. Forceful irrigation with saline solution permitted recanalization. In 1 patient the stent had moved into the upper canaliculus. Because of irritation of the canaliculus it had to be pulled out after 2 months. CONCLUSION: The follow-up is still too short to recommend stent implantation as a real alternative to dacryocystorhinostomy. The main advantages are that the procedure is faster, no incision is necessary, and the local anesthesia is easier. The disadvantage is the need for X-ray examination. 相似文献
96.
Ebba Ch. Schwarz Michael Gerdemann Ricarda Hoffmann Christian Hartmann 《Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft》1999,96(10):635-639
Summary
In our Department of Orthoptics we have seen an increasing number of patients suffering from diplopia after cataract surgery
with IOL implantation. Between 1993 and 1997 the total number of patients with this problem was 24 (2.7 % of all patients,
mean age 71 years, age range 38–88). We addressed the question of whether there is a common pattern of motility dysfunction.
Methods: After evaluation of the clinical history and the basic ophthalmological findings the following parameters were examined:
binocular function (Bagolini test), squint angles (Maddox cross), ocular motility.
Results: The 24 patients could be divided up into three groups. Group 1 consisted of 9 patients (mean age 82 years, range 64–88) who
complained about diplopia because of strabismus incomitans with vertical deviation and restricted motility on the first day
after surgery. In 8 of the 9 patients strabismus surgery was done. Group II consisted of 10 patients (mean age 66 years, range
38–77) who noticed diplopia and strabismus within 7 days after surgery. We found various kinds of heterotropia. Seven of these
patients were operated on and two had a prism correction. Group III consisted of 5 patients (mean age 67 years, range 61–78).
Their already known strabismus paralyticus or concomitans deteriorated, leading to diplopia in some cases. All patients in
this group were operated on.
Discussion: For group I we believe that retro-, para- or peribulbar anesthesia caused the motility dysfunction. In groups II and III
it is unlikely that local anesthesia had a causative role. The prolonged disruption of binocular vision and the abrupt change
in the sensory situation after the cataract operation with lens implantation may be the leading causes for strabismus or deterioration
of a preexisting strabism, respectively.
Conclusions: These patients need a subtil meticulous diagnostic work-up and follow-up because of the possibility of early surgical therapy,
which has a good prognosis. Evaluation of binocular vision and eye movements prior to cataract surgery appears to be helpful
for later strabismic surgery.
相似文献
97.
ORTHOSIPHON ARISTATUS (Orthosiphonis folium DAB 9) was studied with regard to its phenolic constituents. Twenty compounds were isolated and identified on the basis of their spectral characteristics. The compounds included nine lipophilic flavones, two flavonol glycosides, and nine caffeic acid derivatives. The presence of the recently reported methylripariochromene A could not be confirmed. All compounds identified were quantified by HPLC. The caffeic acid derivatives including the major compounds rosmarinic acid and 2,3-dicaffeoyltartaric acid (67% of total identified phenolics) predominated over the flavones (33%) in an aqueous MeOH extract. The predominance of the caffeic acid derivatives was even more pronounced in a hot water extract (94.5% of total identified phenolics) that was comparable to a herbal tea. 相似文献
98.
Ibrahim Chahoud Jutta Hartmann Gabriele M. Rune Diether Neubert 《Archives of toxicology》1992,66(8):567-572
The effects of a single dose of TCDD on the testis were studied in rats. The animals were treated (subcutaneously) once with TCDD doses of 0, 0.5, 1.0, 3.0, 5.0 g/kg body weight. Doses of 3.0 or 5.0 g TCDD/kg reduced the number of spermatids/testis significantly (60% of the controls). Electron microscopic inspection revealed that both doses led to a dissolution on the germinal epithelium. Altered germ cells at all developmental stages occurred in all testes evaluated. Doses of 0.5 or 1.0 g TCDD/kg did not induce any effects in the testis; therefore, under these experimental conditions of single exposure to rats the dose of 1.0 g TCDD/kg can be considered as NOAEL. 相似文献
99.
Chr. Hartmann 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1982,218(2):75-82
Retro-corneal pigmentation as a result of primary (degenerative) or secondary (inflammatory, traumatic) pigment dispersion represents one of the most frequent findings in specular microscopy. The analysis of the pigment distribution patterns of dense deposits like those inKrukenberg spindle (KS) permits the postulation of ahypothesis concerning the development of such typical corneal pigmentations and the pigmentation of the posterior surface of the cornea in general, such as diffuse pigment dispersion (Vogt 1930), which is seen frequently.In a particular case of double KS with extreme myopia and cataract, endothelial morphological findings were documented over a period of 1 year, both before and after cataract extraction. This was done by means of contact and non-contact specular microscopy in various spindle areas.Themorpho-metric studies (cell density/mm2; cell perimeter; largest, smallest and average cell diameter; specific surface; horizontal and vertical cell orientation) were carried out automatically using a computerised video image analyser. The changes in the area of densest pigmentation in the KS centre confirm the histologically proven capacity of pigment phagocytosis by human corneal endothelium. These findings indicate that in specular microscopy, both endothelial cellular surface modifications andintra-cellular changes are documentable. The extracellular pigment deposits can also be shown by means ofindirect specular microscopy, the optical principle of which is described.
Professor Dr. H. Neubauer for his 60th birthday 相似文献
Zusammenfassung Feinste Pigmentablagerungen an der Hornhautrückfläche als Folge einer primären (degenerativen) oder sekundären (entzündlichen, traumatischen) Pigmentdispersion stellen einen der häufigsten Befunde bei der endothelmikroskopischen Untersuchung dar.Die Analyse des Pigmentverteilungsmusters bei dichten Ablagerungen, wie z.B. bei derKrukenbergspindel, erlauben die Aufstellung einerHypothese bezüglich der Entwicklung dieser typischen primären Hornhautpigmentierung und von degenerativen Pigmentierungen der Hornhautrückfläche im allgemeinen, wie der klinisch sehr häufigen senilen, diffusen Pigmentbestäubung.Bei einem ausgewählten Fall von beidseitiger Krukenbergspindel bei hoher Myopie und Katarakt, wurden vor und nach Katarakt-Extraktion in einem Zeitraum von über einem Jahr endothelmorphologische Befunde in verschiedenen Zonen der Pigmentspindel mittels Contact-/Noncontact-Endothelmikroskopie dokumentiert. Diemorphometrischen Untersuchungen (Zelldichte/mm2, Zellumfang; größter, kleinster und mittlerer Zelldurchmesser; spezifische Oberfläche; Zell-Horizontal- und Vertikal-Orientierung) wurden mittelsautomatisierter Endothelanalyse über ein Video-Computer-Bildanalysesystem durchgeführt.Die Veränderungen im Bereich der dichtesten Pigmentablagerungen im Spindelzentrum bestätigen die histologisch gesicherte Fähigkeit des Hornhaut-Endothels zur Pigment-Phagocytose.Die erhobenen Befunde sprechen dafür, daß bei der Endothelmikroskopie nicht nur die Endothelzelloberfläche, sondern auchintrazelluläre Endothelzellveränderungen dokumentiert werden können. Extrazelluläre Pigmentauflagerungen konnen auch mittels indirekter Endothelmikroskopie dargestellt werden, deren optisches Prinzip erklärt wird.
Professor Dr. H. Neubauer for his 60th birthday 相似文献
100.
The alkaloid composition of cell suspension cultures and differentiated plants of LUPINUS POLYPHYLLUS was evaluated using quartz capillary gas-liquid chromatography, GLC-MS and FD-MS. Lupanine (97% of total alkaloids), sparteine, 13-angeloyloxylupanine and 13-tigloyloxylupanine were detected in alkaloid extracts of L. POLYPHYLLUS cell suspension cultures. Lupanine, 13-cis and 13-trans-cinnamoyloxylupanine were found in the spent cell culture medium. No significant difference was found in the alkaloid composition of photomixotrophic and heterotrophic cell strains although the alkaloid content was 5 to 10 times higher in photomixotrophic cell strains. In the respective plants we could identify 18 alkaloids which include the following esters of 13-hydroxylupanine: 13-tigloyloxylupanine, 13-angeloyloxylupanine, 13-cis-cinnamoyloxylupanine, 13-trans-cinnamoyloxylupanine, 13-benzoyloxylupanine, 13-(2-methylbutyryl)-oxylupanine; and 13-vanilloyloxylupanine. 相似文献