应用λ比值查找黄土层中脉管水

西北地区黄土层中的脉管水规模较小，定位困难。视电阻率λ比值在水平及垂直方向均有很高的分辨率。

An Improved Water-filled Pulse Tube Method Using Time Domain Pulse Separation Method

Based on existing low-frequency water-filled impedance tube testing facilities, which is a part of the Low Frequency Facility of the Naval Undersea Warfare Center in Beijing, an improved water-filled pulse tube method is presented in this short paper. This proposed study is significantly different from the conventional pulse tube method because of the capability for a single plane damped sine pulse wave to generate in the water-filled pulse tube with a regular waveform and short duration time of about 1ms. During the generation process of the pulse, an inverse filter principle was adopted to compensate the transducer response. The effect of the characteristics of tube termination can be eliminated through the generation process of the pulse. Reflection coefficient from a water/air interface was measured to verify the proposed method. When compared with the expected theoretical values, a relatively good agreement can be obtained in the low frequency range of 500-2 000 Hz.

Transient small bowel angioedema due to intravenous iodinated contrast media

Three cases of transient proximal small bowel angioedema induced by intravenous administration of nonionic iodinated contrast media (CM) are presented.Computed tomography (CT) images in the venous phase displayed the proximal small bowel with circumferential thickening of the wall including the duodenum and proximal segment of the jejunum.The bowel wall was normal in non-enhanced images,and normal or inconspicuous in arterial phase enhanced images.In one of the three cases,the bowel wall was thickened in venous phase but disappeared in the 40 s delayed phase images.No filling defect was seen in the lumen of the superior mesenteric artery and vein.No peritoneal effusion or mesentery abnormality was found.Each of these patients reported only mild abdominal discomfort and recovered without specific treatment within a short time.Only one patient suffered mild diarrhea after scanning which had resolved by the following day.The transient anaphylactic small bowel angioedema due to intravenous iodinated contrast media was easily diagnosed based on its characteristic CT findings and clinical symptoms.Differential diagnosis may include inflammatory and ischemic bowel disease,as well as neoplasms.A three-phase CT protocol and good under-standing of this disorder are fundamentally important in the diagnosis of this condition.The supposed etiology behind the transient anaphylactic reaction to intravenous administration of iodinated CM in small bowel is similar to other CM-induced hypersensitive immediate reactions.The predilection location of transient anaphylactic bowel angioedema is the small intestine,particularly the proximal segment.A speculated cause may be the richer supply of vessels in the small intestine,ample mucous folds and loose connective tissue in the duodenum and the jejunum.

Evaluation and management of patients with refractory ascites

Some patients with ascites due to liver cirrhosis become no longer responsive to diuretics. Once other causes of ascites such as portal vein thrombosis, malignancy or infection and non-compliance with medications and low sodium diet have been excluded, the diagnosis of refractory ascites can be made based on strict criteria. Patients with refractory ascites have very poor prognosis and therefore referral for consideration for liver transplantation should be initiated. Search for reversible components of the underlying liver pathology should be undertaken and targeted therapy, when available, should be considered. Currently, serial large volume paracentesis （LVP） and transjugular intrahepatic portasystemic stent-shunt （TIPS） are the two mainstay treatment options for refractory ascites. Other treatment options are available but not widely used either because they carry high morlJidity and mortality （most surgical options） rates, or are new interventions that have shown promise but still need further evaluation. In this comprehensive review, we describe the evaluation and management of patients with refractory ascites from the prospective of the practicing physician.

Transcatheter closure of coronary artery fistula using Guglielmi detachable coil

Background Coronary artery fistula （CAF） is a rare anomaly.Transcatheter CAF closure has been introduced using various materials,but only few data are available on the Guglielmi detachable coil （GDC）.The advantage of using GDC for transcatheter CAF closure is more controllable,therefore much safer when compared to other coils.This report is about our experience in transcatheter closure of CAF using fibered GDC in our hospital.Methods ＆ Results From 2002 to 2007,there were 10 patients with CAFs （age range：28 to 56 year-old,7 males） who underwent transcatheter CAF closure.There were a total of 19 CAFs which originated from right coronary （n =5）,left circumflex （n =3）,left anterior descending artery （n =10） and left main trunk （n =1）.Median number of coil deployment for each fistula was 3 （range：1 to 6）.The pulmonary artery was the most common site of the distal communication of CAFs （n =14）,followed by right atrium （n =3）,left atrium （n =1） and left ventricle （n =1）.Immediate coronary angiography after GDC deployment revealed no residual shunt in 12 （63.2％） CAFs,significant reduction of the flow in 5 （26.3％）,while 2 （10.5％） could not be closed due to small size.Nine （90％） patients underwent a repeated angiography within 3 to 8 months.Among 12 CAFs that were occluded immediately post-deployment,there were 2 CAFs with insignificant residual flow.Among 6 CAFs with significantly decreased flow immediately post-deployment,2 were occluded totally in the follow-up angiography.In total,12 （70.5％） CAFs were occluded completely and 5 （29.5％） CAFs still had insignificant residual flow,which did not need any additional coil deployment.During a mean follow up of 4.3 ± 0.7 year,all patients remained symptom and complication free.Conclusions The fibered GDC is a safe and effective method for percutaneous closure of the CAFs.

Lipocalin-2 Test in Distinguishing Acute Lung Injury Cases from Septic Mice Without Acute Lung Injury

Objective To explore whether the amount of lipocalin-2 in the biofluid could reflect the onset of sepsis-induced acute lung injury(ALI) in mice. Methods Lipopolysaccharide(LPS, 10 mg/kg) injection or cecal ligation and puncture(CLP) was performed to induce severe sepsis and ALI in C57 BL/6 male mice randomly divided into 5 groups(n=10 in each group): group A(intraperitoneal LPS injection), group B(intravenous LPS injection via tail vein), group C(CLP with 25% of the cecum ligated), group D(CLP with 75% of the cecum ligated), and the control group(6 sham-operation controls plus 4 saline controls). All the mice received volume resuscitation. Measurements of pulmonary morphological and functional alterations were used to identify the presence of experimental ALI. The expressions of lipocalin-2 and interleukin(IL)-6 in serum, bronchoalveolar lavage fluid(BALF), and lung tissue were quantified at both protein and mRNA levels. The overall abilities of lipocalin-2 and IL-6 tests to diagnose sepsis-induced ALI were evaluated by generating receiver operator characteristic curves(ROC) and computing area under curve(AUC). Results In both group B and group D, most of the "main features" of experimental ALI were reproduced in mice, while group A and group C showed septic syndrome without definite evidence for the presence of ALI. Compared with septic mice without ALI(group A+group C), lipocalin-2 protein expression in septic mice with ALI(group B+group D) was significantly up-regulated in BALF(P<0.01) and in serum(P<0.01), and mRNA expression boosted in lung tissues(all P<0.05). Lipocalin-2 tests performed better than IL-6 tests in recognizing sepsis-induced ALI cases, evidenced by the larger AUC of the former(BALF tests, 0.8800 versus 0.6625; serum tests, 0.8500 versus 0.7000). Using a dual cutoff system to diagnose sepsis-induced ALI, BALF lipocalin-2 test exhibited the highest positive likelihood ratio(13.000) and the lowest negative likelihood ratio(0.077) among the tests of lipocalin-2 and IL-6 in blood and BALF. A statistically significant correlation was found between lipocalin-2 concentration in BALF and that in serum(Spearman r=0.8803,P<0.0001). Conclusions Lipocalin-2 expression is significantly up-regulated in septic ALI mice compared with those without ALI. Lipocalin-2 tests with a dual cutoff system could be an effective tool in distinguishing experimental ALI cases.

Intravenous preemptive analgesia modifies the distribution of lymphocyte subsets after radical mastectomy

Objective: In this study, we evaluated the effect of preemptive analgesia of flurbiprofen axetil (FA) and tramadol on immune response in patients undergoing radical mastectomy. Methods: In this prospective randomized, double-blind, placebo-controlled study, 80 patients were randomly assigned to one of four groups (n = 20). The FA group (group A) patients received FA before tracheal intubation and at the end of surgery. The tramadol group (group B) patients received tramadol before tracheal intubation and at the end of surgery. The control group (group C) patients received saline before tracheal intubation and at the end of surgery. The combination group (group D) patients received FA and tramadol before tracheal intubation and at the end of surgery. Cluster of differentiation and lymphocytes were measured. Results: The CD3, CD4, CD8 and lymphocytes decreased postoperatively of all groups except of group A and D at 0.5 h postoperatively (P < 0.05). The CD3, CD4, CD8 and lymphocytes of group D were higher than those of group C at 0.5 h and 4 h postoperatively (P < 0.05). Conclusion: Preemptive analgesia using flurbiprofen axetil (FA) and tramadol may protect the immune system. The immune protective effect of FA may be better than that of tramadol. The combination of FA and tramadol may be the most effective among all the strategies.