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991.
Background Neonatal branching echogenic streaks in the basal ganglia or 'lenticulostriate vasculopathy' (LSV) has no clear comprehensive aetiology.Objective To provide some clinical evidence, possibly relevant to aetiology, by analysis of a large series.Materials and methods Seventy cases (9 deaths, 3 post mortem) identified between 1981 and 2000 out of 9,138 neonates with routine brain sonograms (578 in a protocol for neonates from HIV+ mothers). Review of maternal/neonatal charts for clinical data and serologic status. Retrospective analysis of sonograms for grading and time course of LSV and coexistent abnormalities.Results LSV was unilateral in 31 cases (22 right), bilateral in 39. Grading separated 8 major, 27 moderate and 35 minor patterns. In 42 cases, LSV was isolated, and in 28 it was mixed with peri-intraventricular haemorrhage grades I or II and/or leucomalacia. LSV was detected in the first postnatal week in 56 instances and appeared later in 13. Disappearance occurred mostly within 2 months. Perinatal circumstances: 13 recipient monochorionic twins (polycythaemia from twin-twin transfusion syndromes), 20 HIV+ mothers (possible immunological disturbances; only 2 infected neonates), 10 congenital anomalies, 1 toxoplasmosis, 1 postnatal cytomegalovirus infection, 25 miscellaneous conditions. Numerous maternal and neonatal factors were non-contributory.Conclusions These results do not support congenital toxoplasmosis, rubella, cytomegalovirus, and herpes (TORCH) infections as the main causative factor. Polycythaemia and various immunological disturbances may be involved, as well as infectious agents not appropriately screened by routine serodiagnoses.  相似文献   
992.
Background Children with recurrent abdominal pain often undergo US to confirm or exclude organic disease.Objective To assess the prevalence of mesenteric lymphadenopathy on US in these children.Materials and methods We prospectively studied 189 children with recurrent abdominal pain with US of the abdomen, using graded compression. The results were compared with 73 children in a control group. The children in both groups were divided into three age groups. The size, number, morphology and location of mesenteric lymph nodes were noted, as well as additional findings. Pediatricians followed the patients from 3 months to 1 year, and a repeat US study was done in 30 children.Results Mesenteric lymphadenopathy was present in 116 of 189 children (61.4%), with the greatest prevalence in boys in the younger age groups. The location of the nodes was mainly in the right lower quadrant. In the control group, 7 of 73 children had mesenteric lymphadenopathy, a significantly lower prevalence than in the study group (P<0.001). Additional findings, apart from lymphadenopathy, were present in 27 (14.2%) of the 189 children in the study group, and in 5 (6.8%) of the 73 children in the control group.Conclusion Mesenteric lymphadenopathy is a common, and often the only abnormal, finding on US in children with recurrent abdominal pain.The Chaim Sheba Medical Center, Tel Hashomer, is affiliated with the Sackler Faculty of Medicine, Tel Aviv University  相似文献   
993.
OBJECTIVE: The purpose of this study was to evaluate a new device that couples any standard transvaginal ultrasound transducer to a special tenaculum by means of a specially designed adaptor that enables real-time ultrasound imaging and guidance of intrauterine surgical procedures. STUDY DESIGN: Forty-five patients who underwent intrauterine surgical interventions were evaluated. Forty of these patients had pregnancy terminations. Three patients had curettage for early pregnancy complications. One patient had a polyp removed, and one patient underwent hysteroscopic submucous myomectomy. Five attending physicians performed 26 procedures. Four residents in training performed 19 procedures. All operators were instructed in the assembly and use of the device before their first procedure. Evaluation of the device was done by means of a detailed questionnaire. RESULTS: The procedures were completed successfully and without complications. The time that was involved for the various components of the surgical procedures was recorded; 83% to 90% of the time the operators felt that the technique increased safety and accuracy for the parameters that were evaluated. They required fewer intrauterine instrument manipulations; in 85% of the cases, they could detect the exact end point of the procedure more accurately. In 12% of cases, the operators felt that the device interfered with the performance of the procedure. CONCLUSIONS: The transvaginal ultrasound-assisted gynecological surgery system provided high-resolution images of the cervical canal and the uterine cavity during all stages of the procedure and provided improved indication of the procedure's end point. The increased safety and accuracy that was reported by most users was encouraging. The transvaginal ultrasound-assisted gynecologic surgery system appears to provide an enhanced alternative to transabdominal ultrasound guidance for intrauterine surgical procedures.  相似文献   
994.
OBJECTIVE: To evaluate the relationship among maternal serum endocrinology, placental karyotype, and intervillous blood flow in missed miscarriage. DESIGN: Cross-sectional study of maternal serum, transvaginal ultrasound/Doppler, and placental cytogenetic and immunohistochemical investigations. SETTING: Tertiary care academic hospital. PATIENT(S): One hundred fifty-two women with missed miscarriage between 7 and 13 weeks of gestation. INTERVENTION(S): Ultrasound features, placental intervillous circulation findings on color Doppler imaging, and maternal serum level of alpha-fetoprotein (AFP), beta-hCG, E(2), P, and inhibin A were compared retrospectively with placenta karyotype and hCG immunochemistry. MAIN OUTCOME MEASURES: Data were analyzed according to karyotype results, presence or absence of an intervillous circulation, and delay between fetal demise and evacuation. RESULT(S): The presence of intervillous blood flow and serum concentrations of the different hormones were independent of placental karyotype. Serum beta-hCG and P were significantly higher in cases with intervillous blood flow. No difference in immunostaining for beta-hCG was found between placental tissues from normal pregnancies and missed miscarriages, but significantly higher villous beta-hCG content was found on Western blotting in miscarriage with a recent fetal demise. CONCLUSION(S): The excessive entry of maternal blood inside the placenta in the early stage of most miscarriages is unrelated to conceptus karyotype, and hCG features may reflect a temporary attempt of the trophoblast to stabilize after the initial oxidative insult.  相似文献   
995.
Recent developments in ultrasound (US) technology have allowed the study of microperfusion in the anterior segment of the eye. Our aim was to determine the effect of the thermal environment on blood flow in the anterior segment. We measured blood flow in the major arterial circle of five rabbits. A 38-MHz US transducer was coupled to the eye with a normal saline water-bath with temperature controlled from 1 degrees C to 38 degrees C. The major arterial circle was localized and imaged using the swept-scan technique and M-mode data were then acquired for measurement of pulsatile flow. Peak systolic and mean velocity averaged 4.51 and 1.32 mm/s, respectively. Positive correlations were found between peak systolic (1.69%/ degrees C) and mean (1.76%/ degrees C) velocities and temperature. Vessel diameter (mean = 178 microm) did not show any significant change with temperature. High-resolution US flowmetry demonstrated decreasing flow rates in the iris with decreasing temperature.  相似文献   
996.
Urethane test objects are available that are more durable than traditional gel-based objects. Their ultrasound (US) propagation speed differs from scanner calibration velocity. This is clearly a disadvantage in checking caliper accuracy, but its effect on other measurements such as resolution is not well known. A test object containing a column of nylon filaments was constructed and filled with water at different temperatures to give US speeds of 1,540 m s(-1) and 1,450 m s(-1). Images of the filaments were digitally captured and analysed to obtain the full-width half-maximum of the target images at each depth. Target image width was greater at 1,450 m s(-1). Measurements were also performed for the two types of tissue-mimicking test objects; results were in close agreement with the water test object. US beam profiles are broader in media with low propagation velocities.  相似文献   
997.
Image compounding reduces the artifacts inherent in ultrasound imaging, but accurate matching of images for compounding depends on their accurate placement in the compound image plane. A method is presented to reduce displacement errors during compounding of ultrasound B-scans of a normal human shank. A genetic algorithm was used to place matching B-scans in the compound image. The method was tested on a phantom and was shown to reduce, but not eliminate, mismatches due to the displacement of B-scans from their original position in the compound image plane. The results can be extended to applications in lower-limb prosthetics, where ultrasound imaging can be used to visualise the internal geometry of amputees' residual limbs.  相似文献   
998.
Introduction It is evident that ultrasound could be a reliable substitute for radiography in very specific cases like stress or undisplaced fractures.Materials and methods Ultrasound was used to examine a physeal fracture of the sternal end of the clavicle in a 3-year-old boy.Results Results included separation and a longer distance between the manubrium and clavicle on the left. A hyperechogenic structure between the manubrium and clavicle was considered to be a metaphyseal fragment. The patient was checked again 3 weeks post-injury. Sonography revealed haematoma resorption as well as callus formation between the fragments and along the medial metadiaphysis of the clavicle.Conclusion Despite the interesting information that could be derived from the ultrasonic investigation of the medial end of the clavicle in our patient, it is mandatory to compare and prove the interpretation of the findings with other conventional methods like X-rays or CT scan.  相似文献   
999.
Classification and imaging of vascular malformations in children   总被引:1,自引:0,他引:1  
Abernethy LJ 《European radiology》2003,13(11):2483-2497
Accurate diagnosis and classification of haemangiomas and vascular malformations is essential for prediction of outcome and rational therapeutic intervention. The purpose of this review is to demonstrate how radiological techniques, including projectional radiography, ultrasound and colour flow imaging, magnetic resonance imaging, and conventional venography and arteriography can aid in the diagnosis and classification of vascular malformations in children, and to guide the radiologist in the use of modern nomenclature.  相似文献   
1000.
Laparoscopic instead of open surgical repair of inguinal hernias is becoming more frequent. Radiologists may expect different postoperative findings depending on the technique used. We studied how radiology had been used postoperatively and what findings were encountered after laparoscopic herniorraphy. Postoperative radiologic examinations related to hernia repair of all consecutive patients that had had laparoscopic herniorraphy in Malmö University hospital between 1992 and 1998 were retrospectively evaluated. A total of 538 groins were included, 3.9% (n=21) of these were postoperatively examined with ultrasound (n=10), herniography (n=7), plain abdominal films (n=2), CT (n=1), or fistulography (n=1). Significant findings were found in five groins, namely, one sinus tract, two hematomas, one small bowel obstruction, and one recurrence of hernia. Four insignificant seromas were found. The characteristics of the findings and pitfalls are described. Symptoms resulting in radiologic examination are rare after laparoscopic herniorraphy. The radiologist must be familiar with the spectrum of such findings.  相似文献   
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