Research on the method of dual-frequency microwave diagnosis of plasma for solving phase integer ambiguity

In this work,microwaves and terahertz waves have performed a dual-frequency combineddiagnosis in high-temperature,large-scale plasma.According to the attenuation and phase shift of electromagnetic waves in the plasma,the electron density and collision frequency of theplasma can be inversely calculated.However,when the plasma size is large and the electron density is high,the phase shift of the electromagnetic wave is large(multiple times 2πperiod).Due to the limitations of the test equipment,the true phase shift is difficult to test accurately or to recover reality.That is,there is a problem of phase integer ambiguity.In order to obtain a phase shift of less than 180°,a higher electromagnetic wave frequency(terahertz wave with 890 GHz)is used for diagnosis.However,the attenuation of the terahertz wave diagnosis is too small(less than 0.1 d B),only the electron density can be obtained,and the collision frequency cannot be accurately obtained.Therefore,a combined diagnosis was carried out by combining twofrequencies(microwave with 36 GHz,terahertz wave with 890 GHz)to obtain electron density and collision frequency.The diagnosis result shows that the electron density is in the range of(0.65–1.5)×1019m^(-3),the collision frequency is in the range of 0.65–2 GHz,and the diagnostic accuracy is about 60%.

COMBINED IMAGING DIAGNOSIS OF PAROTID MASSES

Computed tomography (CT), ultrasonography, sialography, and 99mTc scintigraphy were applied before operation to 108 patients with parotid masses. The results of each technique and the combined study of them were compared with the pathological diagnosis. Ultrasonography was found to be a very effective diagnostic aid in determining the presence of space-occupying lesion in the parotid. CT was the best technique to provide adequately reliable informations regarding the location of the tumor and the relationship between tumor and surrounding tissues. For diagnosing the nature of tumors, ultrasonography combined with sialography was reliable. 99mTc scintigraphy was better than other techniques in diagnosis of adenolymphoma. The diagnostic accuracy of combined diagnosis (90.7%) was higher than those of ultrasonography (83%), CT (80.5%), sialography (79%), and 99mTc scintigraphy (13.9%) alone. The advantage of combined diagnosis was particularly obvious for the diagnosis of low-grade malignant tumors.

Mortality and Morbidity Following Surgery for Primary Malignant Musculoskeletal Tumors in the Pelvis and Limbs: A Retrospective Analysis Using the Japanese Diagnosis Procedure Combination Database

Introduction: Resection of malignant pelvic tumors has long been considered to be associated with higher postoperative mortality and morbidity than resection of malignant limb tumors. We compared the postoperative adverse events of pelvic tumor surgery and limb tumor surgery using a national inpatient database. Methods: We identified patients who underwent surgery for primary musculoskeletal malignant tumors of the pelvis or limbs between July and December in 2007- 2010 using the Japanese Diagnosis Procedure Combination inpatient database. We calculated the risk-adjusted odds ratio for the occurrence of postoperative complications following pelvic tumor surgery with reference to limb tumor surgery using a multivariable logistic regression analysis. Results: Of 3255 eligible patients, 3116 underwent limb tumor surgery and 139 underwent pelvic tumor surgery. In-hospital mortality was 0.6% and 0.7% and postoperative complication rates were 8.2% and 18.7%, respectively. The rate of blood transfusion and duration of anesthesia over 480 min were higher in the pelvic tumor group. Blood transfusion volume and duration of anesthesia were independently associated with worse outcomes, but there was no significant association between tumor location and occurrence of postoperative complications (odds ratio 1.18, 95% confidence interval 0.73 - 1.88, p = 0.502). Conclusions: Blood transfusion volume and duration of anesthesia were significant predictors of outcome. Our data demonstrate that the higher morbidity rate after pelvic tumor resection could result from the larger blood transfusion volume and longer anesthesia duration.

Risk Factors Associated with In-Hospital Post-Chemotherapy Mortality in Patients with Malignant Musculoskeletal Tumors

Introduction: Reducing the in-hospital post-chemotherapy mortality rate in patients with malignant musculoskeletal tumors is important for improving treatment outcome. This study aimed to investigate the risk factors associated with in-hospital post-chemotherapy mortality in patients with primary malignant musculoskeletal tumors. Methods: Using a Japanese national inpatient database, we retrospectively identified 5039 patients (2920 men and 2131 women;mean age, 39 years) who underwent curative chemotherapy for malignant musculoskeletal tumors between 2007 and 2010. We extracted data on the patients’ characteristics, complications, chemotherapeutic agent use, comorbidities, and in-hospital death. Logistic regression analyses were performed to analyze factors affecting in-hospital post-chemotherapy death in these patients. Results: The overall in-hospital mortality rate was 1.1%. Higher in-hospital mortality rates were significantly associated with a greater volume of blood transfusion (>2500 mL) (odds ratio [OR], 49.71;95% confidence interval [CI], 22.24 - 111.12;p < 0.001), diabetes mellitus (OR, 3.05;95% CI: 1.21 - 7.70;p = 0.019), and older age (OR, 3.05;95% CI, 1.11 - 8.37;p = 0.031). Conclusions: Higher in-hospital post-chemotherapy mortality rates were associated with massive blood transfusion, which was associated with a 16-fold higher risk of in-hospital mortality compared with other risk factors. Blood transfusion volume should be considered an important indicator for deciding whether the next cycle of chemotherapy is administered continuously or not.