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151.
The purpose of the present study was to investigate the relationship between Korean language-specific dysgraphia and unilateral spatial neglect in 31 right brain stroke patients. All patients were tested for writing errors in spontaneous writing, dictation, and copying tests. The dysgraphia was classified into visuospatial omission, visuospatial destruction, syllabic tilting, stroke omission, stroke addition, and stroke tilting. Twenty-three (77.4%) of the 31 patients made dysgraphia and 18 (58.1%) demonstrated unilateral spatial neglect. The visuospatial omission was the most common dysgraphia followed by stroke addition and omission errors. The highest number of errors was made in the copying and the least was in the spontaneous writing test. Patients with unilateral spatial neglect made a significantly higher number of dysgraphia in the copying test than those without. We identified specific dysgraphia features such as a right side space omission and a vertical stroke addition in Korean right brain stroke patients. In conclusion, unilateral spatial neglect influences copy writing system of Korean language in patients with right brain stroke.

Graphical Abstract

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152.
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154.
K Ha  M H Freedman  A Hrincu  D Petsche  A Poon  E W Gelfand 《Blood》1985,66(6):1404-1408
Recent studies suggest that lymphoid blast crisis cells of chronic myelogenous leukemia (CML) expressing the common acute lymphoblastic leukemia antigen (CALLA) are B precursor cells, based on the demonstration of immunoglobulin (Ig) gene rearrangement similar to common acute lymphocytic leukemia. There is little evidence to suggest whether the cells with similar lymphoid characteristics in the mixed blast crisis of CML are also committed to B cell lineage. A patient in "mixed" blast crisis of CML was studied. On the basis of morphology, cytochemistry, and immunological studies, the blasts were classified as having either lymphoid or myeloid characteristics. A proportion of the leukemic blasts expressed CALLA, whereas others expressed My7 antigen. In order to characterize both populations of cell further, CALLA+ blasts and My7+ (myeloid) blasts were isolated by fluorescence-activated cell sorting. The My7+ cells were highly proliferative in cell culture blast colony assays, retained the Ph1 chromosome, and were indistinguishable from acute myelogenous leukemia blasts. The CALLA+ cells were also Ph1-chromosome positive, but in contrast, were poorly proliferative in vitro. Of particular note was their retention of germline configuration of Ig genes, thus distinguishing them from blasts in the lymphoid crisis of CML. We conclude that the lymphoid component in mixed blast crisis may represent a stage of differentiation prior to commitment to B lineage.  相似文献   
155.
OBJECTIVES: The goal of this study was to describe the mapping and ablation of polymorphic ventricular tachycardia (VT) after myocardial infarction (MI). BACKGROUND: The initiating mechanisms of polymorphic VT after MI have not been reported. METHODS: Five patients (four males; age 61 +/- 7 years) with recurrent episodes of polymorphic VT after anterior MI (left ventricular ejection fraction 32 +/- 7%) despite revascularization and antiarrhythmic drugs were studied. All patients demonstrated frequent ventricular premature beats (PBs) initiating polymorphic VT. Pace mapping and activation mapping were used to identify the earliest site of PB activity. The presence of a Purkinje potential preceding PB defined its origin from the Purkinje network. Electroanatomic voltage mapping was performed to delineate the extent of MI. RESULTS: The PBs were observed in all cases to arise from the Purkinje arborization in the MI border zone. These PBs were right bundle-branch block in all five patients, with morphologic variations in the limb leads in four; one also had a left bundle-branch block morphology. The coupling interval of the PB to the preceding QRS complex demonstrated significant variations (320 to 600 ms). During PB, the Purkinje potential at the same site preceded the QRS complex by 20 to 160 ms and was associated with different morphologies. Repetitive Purkinje activity was documented during polymorphic VT. Splitting of Purkinje activity and Purkinje to muscle conduction block were also observed. Ablation at these sites eliminated all PBs. At 16 +/- 5 months follow-up using defibrillator memory interrogation, no patient has had recurrence of arrhythmia. CONCLUSIONS: The Purkinje arborization along the border-zone of scar has an important role in the mechanism of polymorphic VT in patients after MI. Ablation of the local Purkinje network allows suppression of polymorphic VT.  相似文献   
156.
BACKGROUND: The use of percutaneous endoscopic gastrostomy (PEG) for enteral nutrition in patients admitted for stroke is difficult, varying and needs specific consideration. There is therefore need for more data on this patient group. We examined the indications, survival, tube removal and time with PEG in stroke patients and in other patients with PEG with the aim of providing guidance for the management of enteral nutrition via PEG in stroke patients. METHODS: Retrospective assessment of data from all stroke patients and patients with other diseases (control group) who had received PEG for enteral nutrition during a period of 8.5 years. RESULTS: Eighty-three stroke patients with dysphagia received PEG after unsuccessful use of nasogastric tubes or long-term tube feeding. Early mortality rate was 19% in the stroke group, 26% in the older group (>74 years) and 12% in the younger group (60-74 years). The PEG tubes were later removed due to swallowing recovery in 20% of the older group and in 31% of the younger group. At 90 days, 50%-60% still needed PEG. The stroke patients were older compared to the control group (n = 115); 30-day mortality was similar but more patients recovered the ability to swallow. CONCLUSIONS: Stroke patients are older than other patients who receive PEG; 27% have swallowing recovery and more than 75% have long-term need for PEG. Nasogastric tubes often fail, and the need for early PEG placement (within 2 weeks) must be assessed in appropriate patients. The patient's prognosis, the objective of nutritional treatment, duration of dysphagia, age and comorbidity should all be taken into consideration.  相似文献   
157.
Asynchronism and right ventricular pacing   总被引:2,自引:0,他引:2  
In patients with congenital heart block (CHB), dual-chamber pacing restores physiological heart rate and atrio-ventricular synchronization. However, patients with narrow QRS junctional escape rhythm may be deleteriously affected by long-term, permanent, apical ventricular pacing. We assessed the impact of apical ventricular pacing on echocardiographic ventricular dyssynchrony and hemodynamic parameters. METHODS: Fourteen CHB adults (23 +/- years, 58% male), with a DDD transvenous pacemaker and a junctional escape rhythm (QRS<120 ms) before implantation, were studied. Echocardiography coupled with tissue Doppler imaging (TDI) and Strain rate was performed in spontaneous rhythm (VVI mode 30/mn) and during atrio-synchronized ventricular pacing. RESULTS: The heart rate (43 +/- 09 vs 68 +/- 07: p<0.01), cardiac output (2.9 +/- 0.7 vs 3.7 +/- 0.6 L/min) and left ventricular filling time (325 +/- 38 vs 412 +/- 51 ms; p<0.01) were significantly less in the escape spontaneous rhythm compared with atrio-ventricular synchronized apical pacing. However, interventricular dyssynchrony (28 +/- 12 vs 59 +/- 25 ms, p<0.05), intra-left ventricular dyssynchrony (36 +/- 11 vs 57 +/- 29 ms; p<0.05), extent of left ventricular myocardium displaying delayed longitudinal contraction (26 +/- 10 vs 39 +/- 17%: p<0.05) were significantly less in the escape rhythm compared with paced rhythm. CONCLUSION: Once implanted with a DDD pacemaker, CHB patients present with increased cardiac output secondary to the restoration of physiological heart rate and improved diastolic function. However, the apical site is not optimal, as it creates detrimental ventricular dyssynchrony in patients with previous nearly physiological ventricular activation. Alternative pacing sites should be investigated.  相似文献   
158.
Follicular lymphoma international prognostic index   总被引:14,自引:14,他引:14       下载免费PDF全文
The prognosis of follicular lymphomas (FL) is heterogeneous and numerous treatments may be proposed. A validated prognostic index (PI) would help in evaluating and choosing these treatments. Characteristics at diagnosis were collected from 4167 patients with FL diagnosed between 1985 and 1992. Univariate and multivariate analyses were used to propose a PI. This index was then tested on 919 patients. Five adverse prognostic factors were selected: age (> 60 years vs 60 years), Ann Arbor stage (III-IV vs I-II), hemoglobin level (< 120 g/L vs 120 g/L), number of nodal areas (> 4 vs 4), and serum LDH level (above normal vs normal or below). Three risk groups were defined: low risk (0-1 adverse factor, 36% of patients), intermediate risk (2 factors, 37% of patients, hazard ratio [HR] of 2.3), and poor risk ( 3 adverse factors, 27% of patients, HR = 4.3). This Follicular Lymphoma International Prognostic Index (FLIPI) appeared more discriminant than the International Prognostic Index proposed for aggressive non-Hodgkin lymphomas. Results were very similar in the confirmation group. The FLIPI may be used for improving treatment choices, comparing clinical trials, and designing studies to evaluate new treatments.   相似文献   
159.
Stretchable gas sensors are important components of wearable electronic devices used for human safety and healthcare applications. However, the current low stretchability and poor stability of the materials limit their use. Here, we report a highly stretchable, stable, and sensitive NO2 gas sensor composed of reduced graphene oxide (RGO) sheets and highly elastic commercial yarns. To achieve high stretchability and good stability, the RGO sensors were fabricated using a pre-strain strategy (strain-release assembly). The fabricated stretchable RGO gas sensors showed high NO2 sensitivity (55% at 5.0 ppm) under 200% strain and outstanding mechanical stability (even up to 5000 cycles at 400% applied strain), making them ideal for wearable electronic applications. In addition, our elastic graphene gas sensors can also be woven into fabrics and clothes for the creation of smart textiles. Finally, we successfully fabricated wearable gas-sensing wrist-bands from superelastic graphene yarns and stretchable knits to demonstrate a wearable electronic device.

Highly stretchable, mechanically stable and weavable RGO elastic electronic yarns were developed using dip-coating with pre-straining. We demonstrate wearable gas sensors that can be worn on the wrist.  相似文献   
160.
We have developed hybridization-sensitive fluorescent oligonucleotide probes that, in the presence of quencher strands, undergo efficient fluorescence quenching through the formation of partial DNA/DNA duplexes. In the presence of target RNA, rapid displacement of the quencher strands results in highly enhanced fluorescence.

We have developed hybridization-sensitive fluorescent oligonucleotide probes that, in the presence of quencher strands, undergo efficient fluorescence quenching through the formation of partial DNA/DNA duplexes.

The detection of biomolecules is an important part of any investigation into their biological mechanisms and phenomena. Fluorescence-based methods are particularly useful for providing interpretable signals for various targets (e.g., genes, proteins, small molecules). When nucleic acids are used as probes, they can provide sequence-specific information regarding the binding (through hydrogen bonding) of target nucleic acids. Because of their high sequence-specificity, many fluorescent hybridization probes, including molecular beacons (MBs), have been developed and applied for nucleic acid detection and visualization.1,2In previous studies, we found that a quencher-free molecular beacon (QF-MB) containing the pyrene-modified nucleoside PyU exhibited a high fluorescence enhancement in the presence of trinucleotide repeats, especially for RNA.3,4 Among various fluorescent nucleobase derivatives, uracil derivatives have been particularly useful for selective detection of specific sequences, taking advantage of changes in photoinduced electron transfer between the fluorophore and the neighboring base.3–5 To apply such systems to various other target sequences, here we designed fully complementary sequences and incorporated the internal fluorescent nucleoside PyU in place of a thymine residue, resulting in a significantly increased fluorescence signal based on strand displacement (Fig. 1). Incorporation of a PyU unit in a single strand of the probe sequence and hybridization with a strand partially complementary to the probe strand containing a pyrene unit as a fluorescence quencher can lead to improved discrimination factors.4,6 Such partially double-stranded probes have several attractive features.Open in a separate windowFig. 1(A) Schematic representation of the strand displacement process developed in this present system. (B) Structures of the internal fluorophore PyU.First, the probe sequence does not require an additional sequence in its strand that is not complementary to the target sequence to ensure formation of a secondary structure (e.g., a hairpin). Such additional sequences might interfere with the specific hybridization between the probe and the target sequence. Accordingly, double-stranded fluorescence probes should allow the specific detection of many kinds of targets. Second, the highly quenched initial fluorescence signal, due to the formation of a partial duplex, results in significantly increased fluorescence in the presence of the target; the incorporation of a hybridization-sensitive internal fluorophore provides a stable and sensitive fluorescence signal upon perfect hybridization with the target.Cofilin is a protein that regulates the activity of actin, which is related to the formation of the cytoskeleton in cells. Actin plays a crucial role in the growth and elongation of cells,7 especially in neurons and, therefore, in the control of neurotransmission. We designed probe strands complementary to the 3′-untranslated region (3′-UTR) of target cofilin mRNA and synthesized three kinds of 19-mer probe strands (P1–P3) containing one or two PyU units in each strand (Fig. 2A and S1, ESI). The fluorescence intensities of P1 and P3 increased dramatically after binding with the target RNA T19—by 17.6- and 16.0-fold, respectively. For the probe P2 (in which the PyU residue was located close to the 3′-end), however, the fluorescence enhancement was very low: only 1.8-fold (Table S2, ESI). We assume that terminal modification of the PyU unit in the probe resulted in weak base pairs around the PyU residue than did central modification, resulting in a decrease in fluorescence enhancement (Table S3, ESI).8 Because flanking base pairs around the PyU unit are relatively less rigid compared to central base pairs, the microenvironment of PyU in the duplex formed from P2 and T19 is different from the central modification. Therefore, the fluorescence intensity did not increase significantly compared to the single-stranded P2. The absorption spectrum of P2 in the presence of T19 exhibited a relatively less intense absorption band than that of the duplex formed from P1 and T19—the latter featured an intense signal corresponding to the high fluorescence intensity (Fig. S1, ESI).9,10 Even though two PyU units were incorporated into the single strand P3, its fluorescence enhancement was similar to that of probe P1 containing only one PyU unit. Among other examined probe sequences complementary to other parts of 3′-UTR in cofilin mRNA, P6 (containing two PyU units) also exhibited fluorescence intensity similar to those of P4 and P5, single-PyU – containing probes each modified in the central position (Fig. S2, ESI). These results suggest that single modification of a PyU unit in the probe sequence is more efficient than dual modification, in terms of inducing high fluorescence enhancement with target RNA.Oligonucleotide sequences of probe and target strands
NameSequence
P15′-GGT GCC PyUAG GAC GGG ACT T-3′
P25′-GGT GCC TAG GAC GGG ACPyU T-3′
P35′-GGT GCC PyUAG GAC GGG ACPyU T-3′
U53′-CA CGG PyUTC CTG-5′
U63′-CCA CGG PyUTC CTG C-5′
T19a5′-a agu ccc guc cua ggc acc-3′
T19-Ua,b5′-a agu ccc guc cu ggc acc-3′
T19-Ga,b5′-a agu ccc guc cu ggc acc-3′
T19-Ca,b5′-a agu ccc guc cu ggc acc-3′
Open in a separate windowaTarget RNA sequence.bUnderlined letter indicates a single mismatched base.Open in a separate windowFig. 2(A, B) Fluorescence emission spectra of (A) the probes P1–P3 with T19 and (B) the probe P1 with U5 and U6. (C) Fluorescence enhancements (F/F0) at 432 nm of P1 in the presence of U5 and U6 upon binding with T19; 1.0 μM of samples in 100 mM Tris-HCl buffer (pH 7.2), 100 mM NaCl and 10 mM MgCl2; annealing: 90 °C; excitation wavelength: 380 nm; excitation/emission slit: 5 nm/5 nm; F: fluorescence intensity at 432 nm of the probe P1 with the target RNA T19 in the absence or presence of a quencher strand U5 and U6; F0: fluorescence intensity at 432 nm of the probe P1 in the absence or presence of a quencher strand U5 and U6.Next, to improve the fluorescence enhancement in the presence of the target, the background signal of the probe was decreased by mixing it with a pyrene-modified short oligonucleotide, a so-called “quencher strand”, capable of quenching the fluorescence of the PyU unit. Two pyrene units on the opposite side in the duplex resulted in fluorescence quenching because pyrene moieties are stacked each other and located in a highly polar environment.4,9 Such duplexes containing probe and quencher strands would have to undergo displacement of the quencher strand prior to hybridization of the target strand. First, we tested the effects of a PyU residue located in the quencher strand at the central position, opposite the PyU residue in the probe strand, potentially minimizing the fluorescence of the PyU residue in the probe strand through π-stacking of the two pyrene units in the duplex.4,11 We synthesized the quencher strands U5 and U6, each containing a PyU residue, and examined the relationship between the quenching efficiency and stable hybridization of the probe/quencher duplexes upon varying the length of the quencher strand (Fig. 2B). The more stable the partial duplex is formed, the more effective stacking interaction between pyrene moieties close to each other can be possible.12 In the presence of the PyU-modified quencher strands, the quenching efficiency of the probe at 435 nm was 65% for U5 and 80% for U6. As a result, the enhancements in fluorescence for the probe in the presence of the target T19 were 51.5- and 66.7-fold for U5 and U6, respectively (Fig. 2C and S7, ESI) much higher than that for P1 alone. Notably, these fluorescence signals were generated not only from the probe/target duplexes but also from the released quencher strands (i.e., the single-stranded quencher strands also exhibited fluorescence to some degree). Therefore, the actual fluorescence signal arising from hybridization of the probe with the target was slightly lower than that observed in the fluorescence spectra; we estimated that the additional signals due to the release of U5 and U6 increased the fluorescence intensity by 7% (Fig. S7, ESI). In other words, the released quencher strands added to the fluorescence enhancement of the DNA/RNA duplex. Moreover, we also tested the effect of incorporating a dabcyl derivative, DabU, as a typical fluorescence quencher on the quencher strand and compared its effects with those of the quencher strand containing a PyU unit (Table S4, Fig. S4, ESI). The PyU-modified quencher strands provided the probe with similar quenching in fluorescence as did DabU-modified quencher strands of the same length (Fig. S8 and S9, ESI). The melting temperatures (Fig. S10, Table S5, ESI) of the duplexes of the PyU-modified quencher strands and P1 (for U5 and U6 with P1: 60.1 and 66.0 °C, respectively) were higher than those of the natural strands and P1 (for N5 and N6 with P1: 46.8 and 56.0 °C, respectively); the former were stabilized through π-stacking of the PyU units (Fig. S5 and S6, ESI). The formation of duplexes from the probe and quencher strands was evident also in circular dichroism (CD) and polyacrylamide gel electrophoresis (PAGE) experiments (Fig. S11 and S12, ESI).To confirm the effective strand displacement of the quencher strand from the probe strand, we conducted time-dependent fluorescence experiments after addition of the target RNA T19 to probe/quencher duplexes (Fig. 3). After addition of the target strand to the single strand of P1, hybridization was complete within 30 min (i.e., the increase in fluorescence at 435 nm was minor thereafter). In contrast, the fluorescence intensity of P1 in the presence of the 11-mer quencher strand U5 was relatively rapid, reaching equilibrium after 20 min; for the 13-mer strand U6, however, equilibrium was reached within 35 min. Thus, compared with the single-stranded probe P1, the hybrid of P1 with U5 reacted more rapidly with the target T19, but the reaction time of the hybrid of P1 with U6 responding to the target T19 was slightly slower than that of P1 in the absence of a quencher strand. We suspect that the probe strand in the absence of a quencher strand was stabilized by stacking of the nucleobases; the probe would take some time to hybridize with the target RNA, requiring unfolding of its stacked bases. For the partially hybridized duplexes, however, the non-bonded sequence of the probe would be exposed, facilitating hybridization with the target strand. As a result, the response of P1 in the presence of U5 toward the target RNA was slightly faster than that of single-stranded P1 alone. Thus, as the length of the non-bonding sequence of P1 in the partial duplex decreased by increasing the length of quencher strand, the rate of strand displacement decreased accordingly.13–16 Indeed, the reaction time for the probe strand in the presence of the 15-mer strand U7 was much longer than those in the presence of the 11- and 13-mer quencher strands, because only a four-nucleotide sequence was available for hybridization of the target stand T19 (Fig. S13, ESI); in addition, the equilibrium of the reaction shifted to the left, in conjunction with a smaller enhancement in fluorescence.Open in a separate windowFig. 3Time-dependent fluorescence of P1 in the presence of U5 and U6 after addition of T19; 1.0 μM of samples in 100 mM Tris-HCl buffer (pH 7.2), 100 mM NaCl and 10 mM MgCl2; excitation wavelength: 380 nm; emission wavelength: 435 nm; excitation/emission slit: 5 nm/5 nm; temperature: 20 °C.We also tested the selectivity of the probe P1 itself against single-base-mismatched target RNA (Fig. 4, Open in a separate windowFig. 4Fluorescence emission spectra of P1 in the presence of single-base-mismatched target RNA; 1.0 μM of sample in 100 mM Tris-HCl buffer (pH 7.2), 100 mM NaCl and 10 mM MgCl2; annealing: 90 °C; excitation wavelength: 380 nm; excitation/emission slit: 5 nm/5 nm.In conclusion, we have developed a double-stranded duplex that functions as a universal probe that is highly specific for the sequence of its target RNA—in this case, for cofilin mRNA. When the PyU-modified probe strand was partially hybridized with quencher strands containing a PyU unit, the fluorescence intensity decreased dramatically as a result of π-stacking of the PyU units. The probe/quencher hybrids provided even greater fluorescence enhancements after stable binding of the target RNA strand with the additional signal from the released quencher strand further improving the fluorescence detection of the target RNA.  相似文献   
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