Flow-through electrode system (FES): An effective approach for biofouling control of reverse osmosis membranes for municipal wastewater reclamation

Emerging electrochemical disinfection techniques provide a promising pathway to the biofouling control of reverse osmosis (RO) process. However, the comparative effectiveness and mechanism of it under flow-through conditions with low voltage remains unclear. This study investigated the effect of a flow-through electrode system (FES) with both direct current (DC) and alternating pulse current (AC) on RO biofouling control compared with chlorine disinfection. At the initial stage of biofouling development, the normalized flux of AC-FES (67% on Day 5) was saliently higher than the control group (56% on Day 5). Subsequently, the normalized fluxes of each group tended similarity in their differences until the 20th day. After mild chemical cleaning, the RO membrane in the AC-FES group reached the highest chemical cleaning efficiency of 58%, implying its foulant was more readily removable and the biofouling was more reversible. The biofouling layer in the DC-FES group was also found to be easily cleanable. Morphological analysis suggested that the thickness and compactness of the fouling layers were the major reasons for the fouling behavior difference. The abundance of 4 fouling-related abundant genera (>1%), which were Pseudomonas, Thiobacillus, Sphingopyxis, and Mycobacterium exhibited a salient correlation with the biofouling degree. The operating cost of FES was also lower than that of chlorine disinfection. In summary, AC-FES is a promising alternative to chlorine disinfection in RO biofouling control, as it caused less and easy-cleaning biofouling layer mainly due to two advantages: a) reducing the regrowth potential after disinfection of the bacteria, leading to alleviated initial fouling, (b) reshaping the microbial community to those with weaker biofilm formation capacity.

High-efficiency and low-carbon inactivation of UV resistant bacteria in reclaimed water by flow-through electrode system (FES)

With the increasingly serious shortage of water resources globally, it has been paid more attention on how to secure the biosafety of reclaimed water and other non-traditional water sources. However, the 3 most applied disinfection technics, which are chlorine, ultraviolet (UV), and ozone disinfection, all have their disadvantages of selecting undesired bacteria and low energy utilization efficiency. Electrode disinfection is a promising solution, but the current electrode disinfection process still needs to be optimized in terms of the use conditions of the configuration reactivation. In this paper, we built a flow electrode system (FES). To evaluate the disinfection techniques more precisely, we isolated ultraviolet-resistant bacteria (URB) bacteria from the water of the full-scale water plant and tested the disinfection performance of FES and UV. The inactivation rate, reactivation potential, and energy consumption were analyzed. FES could inactivate 99.99 % of the URB and cause irreversible damage to the residual bacteria. FES could make all bacteria strains apoptosis in the subsequent 24 h of storage after alternating pulse current (APC) treatment, 3 V, within 27.7 s. Besides, the energy consumption of FES is about 2 orders lower than that of UV disinfection under the same inactivation rate. In summary, APC-FES is an efficient and low-carbon alternative for future water disinfection, which could achieve the ideal disinfection effect of a high inactivation rate, no reactivation, and low energy consumption.

Modeling and optimization of synergistic ozone-ultraviolet-chlorine process for reclaimed water disinfection: From laboratory tests to software simulation

The ozone-ultraviolet (UV)-chlorine process is a highly effective method of disinfection in water reuse system, but currently still lacks precise quantification and accurate control. It is difficult to determine the dosage of each disinfectant because of the complex interactions that occur between disinfection units and the complicated mathematical calculation required. In this study, we proposed a dosage optimization model for ozone-UV-chlorine synergistic disinfection process. The model was able to identify the cost-effective doses of the disinfectants under the constraints of microbial inactivation, decolorization, and residual chlorine retention requirements. Specifically, the simulation of microbial inactivation rates during synergistic disinfection process was accomplished through quantification of the synergistic effects between disinfection units and the introduction of enhancement coefficients. In order to solve this optimization model rapidly and automatically, a MATLAB-based software program with graphical user interface was developed. This software consisted of calibration unit, prediction unit, assessment unit, and optimization unit, and was able to simulate synergistic ozone-UV-chlorine process and identify the optimal dose of ozone, UV, and chlorine. Validation experiments revealed good agreements between the experimental data and the results calculated by the developed software. The developed software is believed to help the water reclamation plants improve disinfection efficiency and reduce the operational costs of synergistic disinfection processes.

[Relationship of serum uric acid with prediabetes and newly detected type 2 diabetes mellitus]

Objective: To evaluate the relationship of serum uric acid with prediabetes and newly detected type 2 diabetes mellitus (T2DM) in adults. Methods: Data were obtained from the baseline investigation of Songjiang Peak-Plan cohort. According to the baseline fasting plasma glucose and glycosylated hemoglobin, the eligible subjects were divided into normal blood sugar group, prediabetes group, and newly detected T2DM group. Unconditional logistic regression model was used to explore the effect of serum uric acid level on prediabetes and newly detected T2DM, and restricted cubic spline (RCS) function was used to explore the nonlinear dose-response relationship of serum uric acid level with the prevalence of prediabetes and newly detected T2DM. Results: A total of 30 375 subjects were included in the analysis, with an average age of (55.36±11.52) years, and 60.2% (18 299) of them were women. The baseline survey found that the prevalence of prediabetes was 38.6% (11 739 cases), and the prevalence of newly detected T2DM was 6.6% (1 992 cases). Logistic regression analysis showed that, in women, for every 10µmol/L increase in serum uric acid, the risk of developing prediabetes and T2DM s increased by 2.4% (OR=1.024, 95%CI: 1.018-1.030), and 1.5% (OR=1.015, 95%CI: 1.005-1.025), respectively; in men, for every 10 µmol/L increase in serum uric acid, the risk of developing prediabetes and T2DM decreased by 0.8% (OR=0.992, 95%CI: 0.987-0.998) and 5.0% (OR=0.950, 95%CI: 0.939-0.960), respectively. The RCS function showed that the serum uric acid level showed a nonlinear dose-response relationship with newly detected T2DM (P=0.017), but not with prediabetes (P=0.670) in women and showed a nonlinear dose-response relationship with both prediabetes (P=0.040) and newly detected T2DM (P<0.001) in men. Conclusions: Adult women are at increased risk of prediabetes and newly detected T2DM with increase of serum uric acid level, and adult men are at decreased risk of newly diagnosed T2DM with the increase of serum uric acid level. There was no significant relationship between serum uric acid level and prediabetes in men.

[Lower extremity lymphedema as the initial symptom of malignant disease]

To investigate the diagnosis of malignancy with lower extremity lymphedema as the initial manifestation. We performed a retrospective study of 33 patients with malignant lymphedema treated at the Department of Lymphatic Surgery, Beijing Shijitan Hospital, Capital Medical University, from May 22, 2007 to December 31, 2018. A total of 33 cases of lower extremity lymphedema caused or aggravated by malignant tumors were found. The age range of 33 patients with malignant lymphedema was 21 to 84 years. Twenty-two patients were male, and 11 patients were female, with a mean age of (57.5±15.0) years. The time from the occurrence of lymphedema to the diagnosis of malignant tumors ranged from a month to 2 years. The proportion of patients with abnormal tumor markers was 88.9% (24/27), the prevalence of anemia among patients with malignant lymphedema was 42.4% (14/33), and the positive rates of ultrasonography, CT, MRI, and radionuclide imaging were 100.0% (17/17), 100.0% (25/25), 100.0% (4/4) and 60.0% (12/20), respectively. Twenty-seven cases with malignant tumors were confirmed by pathological diagnosis. To avoid delays in the diagnosis and therapy of malignant lymphedema, physicians should actively look for signs or symptoms of lymphedema during the follow-up period and promptly manage patients developing problems.

[Clinical features of primary isolated chylopericardium: a retrospective review study]

Objective: To examine the clinical characteristics and abnormal reflux branches of primary isolated chylopericardium. Methods: Totally 43 patients with primary isolated chylopericardium at Department of Lymphatic Surgery, Affiliated Beijing Shijitan Hospital,Capital Medical University from June 2007 to January 2018 were recruited in this study. There were 21 males and 22 females, aging (23.0±15.9) years (range: 2 to 57 years). The levels of triglyceride, total cholesterol, total protein and albumin in pericardial effusion and blood were compared by paired-t test, and the characteristics of lymphatic system in direct lymphangiography and postoperative CT were analyzed. Results: Pericardial effusion was mainly milky white and monocytes, and 95.3%(41/43) were positive for Rivalta test. The level of triglyceride in pericardial effusion was significantly higher than that of blood ((9.67±5.11) mmol/L vs. (1.28±0.89) mmol/L, t=10.557, P<0.01), and the levels of total cholesterol ((2.19±0.52) mmol/L vs. (4.12±1.06) mmol/L, t=-3.732, P<0.01), total protein ((61.25±16.17) g/L vs. (68.26±8.30) g/L, t=-2.958, P=0.005) and albumin ((36.63±7.06) g/L vs. (42.32±4.73) g/L, t=-5.747, P<0.01) were significantly lower than that of blood. In the direct lymphangiography, the imaging of iliac and retroperitoneal lymphatics showed dilated or tortuous in 90.7% (39/43), the thoracoabdominal segment of thoracic duct showed dilation in 46.5% (20/43), and cervical thoracic duct imaging showed dilation in 44.2% (19/43) and stenosis in 55.8% (24/43). The image of lipiodol flowing into the vein showed obstruction at the venous angle. There were 60.5%(26/43) of the patients with lipiodol reflux through the bronchomediastinal trunk (type Ⅰ), 11.6%(5/43) with lipiodol diffusion to the pericardium through the abnormal pathway from the thoracic segment of the thoracic duct (type Ⅱ), while no communication pathway between the thoracic duct and the pericardial cavity (type Ⅲ) found in 27.9%(12/43). CT images obtained after the direct lymphangiography showed 34.9%(15/43) had abnormal distribution of lipiodol in pericardium, mediastinal lymph nodes and lung hilar lymph nodes, 46.5%(20/43) in mediastinal lymph nodes and lung hilar lymph nodes, 14.0%(6/43) only mediastinal lymph nodes, 4.6%(2/43) had no lipiodol in the above areas. Conclusions: Pericardial effusion compared with same period blood, has higher triglyceride, lower total cholesterol, total protein and albumin. The obstruction of the cervical segment of the thoracic duct and the formation of abnormal reflux branches would be corelative to primary isolated chylopericardium.

[Influence of glottal stops on nasalance and velopharyngeal closure status after cleft palate surgery]

Objective: To investigate the influence of glottal stops for the relationship between nasalance and velopharyngeal closure status of cleft palate patients after surgery. Methods: A total of 71 patients with postoperative cleft palate speech disorders treated in the Department of Oral and Maxillofacial surgery, School of Stomatology, Peking University from August 2004 to August 2010 were included. The compensated speech evaluation of cleft palate with or without glottic occlusion was performed in 50 males and 21 females with an average age of (15.9±6.2) years old. The nasal sound meter and nasopharyngeal fiber endoscope were used to record the nasal phonation rate and the score of nasopharyngeal fiber endoscopic visual analog scale (VAS) of the patients. According to the results of glottic plug speech evaluation, the patients were divided into three groups: whole group (without glottic plug), glottic plug group and silent glottic plug group. The nasal phonation rate values and VAS values of 11 speech samples (unit vowel No. 1-3, continuous syllable No. 4-9, sentence 10-11) of the three groups were compared by Pearson analysis. Results: There were 71 patients in the whole group, 34 patients in the glottic plug group and 37 patients in the silent glottis group. There was a negative correlation between nasal phonetic rate and VAS of 11 speech samples in the whole group, however there were no significant difference (r>-0.179 and<-0.017, P>0.017) and no significant correlation between nasal phonetic rate and VAS in glottic occlusion group (r>-0.196 and<-0.017, P>0.05). There was a significant negative correlation between nasal phonetic rate and VAS value of all but No. 1, 3 and 11 speech samples in silent door plug group (P<0.05), among which No. 7 speech sample was the most sensitive sample (r=-0.557, P<0.05). Conclusions: The present study showed the glottal stops could affect the evaluation of the velopharyngeal closure function by using nasometer. Glottal stops should be considered as one important factor for the nasalance.

[Effects of simultaneous nasometer and nasopharyngeal fibroscopic examination on the value of nasalization rate in cleft palate patients]

Objective: To evaluate the changes of nasalance when cleft palate patients examined using nasometer and nasopharyngeal fiberscopy simultaneously. Methods: A total of 33 cleft palate patients from August 2004 to August 2010 were examined by nasopharyngeal fiber endoscopy and nasometer simultaneously. The nasalance of 33 voice samples was compared under two situations only nasometer and nasometer with nasopharyngeal fiberscopy. Results: The statistics showed that the nasalance value of 33 voice samples of 33 participants under different situations were no significant difference through paired t-test (P>0.05). Conclusions: Nasopharyn fiber endoscopy had no influence to the results of the nasalance value under simultaneous condition. The nasometer and nasopharyn fiber endoscopy can be applied to evaluate the velopharyngeal function of cleft palate patients simultaneously.

Identification and diversity of Y-chromosome haplotypes in Qinghai yak populations

The aim of the present study was to perform a preliminary analysis of the characterization and diversity of Y-chromosome haplotypes/haplogroups in yak of Qinghai Province, China. A total of 322 male yaks from nine populations belonging to three officially recognized breeds (Gaoyuan, Huanhu and Datong) were sampled. Animals were genotyped using six previously reported Y-SNPs present in the SRY, USP9Y, UTY, AMELY and OFD1Y genes and four new Y-SNPs in the OFD1Y gene (g.569A>C, g.578A>C, g.608G>T and g.653G>C) identified in this study. Seven Y-chromosome haplotypes (H1-H7) were identified according to the combination of the 10 Y-SNPs. H1, H2 and H6 were the most common and shared haplotypes across all yak populations/breeds. Private haplotypes H3 and H7 were detected in the Datong breed; H4 in Guoleimude, Qumalai, Qilian, Tianjun and Ganglong populations; and H5 in Qumalai of Gaoyuan breed. Haplotype clustering and network analyses inferred two haplogroups, Y1 and Y2, indicating two divergent lineages of paternal origins of Qinghai yak. The analysis of molecular variance showed a significant difference among individuals (P < 0.0001) with more than 93% of the total genetic variation present within populations, suggesting a weak genetic structure among Qinghai yak populations. The overall Y-haplotype diversity was 0.538 ± 0.028, showing a relatively high diversity in Qinghai yak. The Gaoyuan and Datong breeds had similar haplotype diversities (0.547 ± 0.030 and 0.553 ± 0.083, respectively), which were higher than that of the Huanhu breed (0.441 ± 0.098). Our results support the conservation and sustainable use of unique yak genetic resources in Qinghai.

[Liposuction combined with lymphatico-venous anastomosis for treatment of secondary lymphedema of the lower limbs: a report of 49 cases]

Objective: To study the clinical effects of liposuction combined with lymphatico-venous anastomosis for treatment of secondary lymphedema of the lower limbs. Methods: A retrospective analysis was performed for 49 patients who had undergone liposuction combined with lymphatico-venous anastomosis to treat secondary lymphedema of the lower limbs at Department of Lymph Surgery, Beijing Shijitan Hospital from November 2013 to February 2015.All patients were female aging from 31 to 70 years with median age of (52±10)years.All patients had history of pelvic surgery.There were 32 cases with cervical carcinoma, 11 cases with endometrial cancer, 1 case with ovarian cancer who accepted radical hysterectomy, 2 cases with benign tumor who accepted resection, 2 cases accepted inguinal lymph node dissection, 1 case with rectal cancer accepted radical resection.There were 30 cases with history of radiation therapy and 23 cases with history of erysipelas recurrent((2.1±3.9)/year). The limb swelling degree in preoperative and postoperative patients was explored using one-way analysis of variance with replicate measures and paired sample t-test. Meanwhile the incidence of lymphogenous infection was used as an evaluation of operation efficacy. Results: The mean lower limb circumference difference at 7 days, 6 months and 12 months was (0.17±1.36)cm, (1.25±1.62)cm and(1.58±1.56)cm, respectively, which was significantly decreased compared with preoperative((4.92±2.16)cm) (t=-5.712, -5.777, -5.765; all P<0.01). The mean lower limb volume difference at 7 days, 6 months and 12 months was (522±799)ml, (726±973)ml and (889±895)ml, respectively, which was significantly decreased compared with preoperative((2 729±1 335) ml)(t=-5.905, -6.093, -5.777; all P<0.01). The incidence of erysipelas was 0.0(0.0, 0.0)/6 months within 6 months after operation and 0.0(0.0, 0.0)/6 months within 6-12 months after operation, which was significantly lower than that before operation(0.0(0.0, 2.0)/year). The feeling of tightness and heaviness of the limb was significantly improved compared with preoperative. Conclusion: Liposuction combined with lymphatico-venous anastomosis is an effective method for the treatment of secondary lymphedema of the lower limbs.

Y-STR INRA189 polymorphisms in Chinese yak breeds

To further explore Y-STR INRA189 polymorphisms in the yak, and to determine the genetic differences among yak breeds, genotyping analysis of INRA189 in 102 male yak individuals from three yak breeds in Qinghai Province of China was performed. Genotyping revealed the presence of four alleles, with sizes of 149, 155, 157, and 159 bp, respectively. Of these, the 157-bp allele, which was found with the highest frequency in the three yak breeds, was the dominant allele. Interestingly, the 149-bp allele was only detected in the Gaoyuan breed, and the 159-bp allele was only found in the Huanhu and Datong breeds. Only the 157- and 155-bp alleles were found in all three yak breeds. Taking the three yak breeds as a single population, the frequency of these four alleles was 0.0294, 0.0686, 0.8628, and 0.0392, respectively. The average polymorphism information content in the three yak breeds was 0.2379, indicating that the INRA189 was a low polymorphic Y-STR marker in yak.

Global microRNA profiles and signaling pathways in the development of cardiac hypertrophy

Hypertrophy is a major predictor of progressive heart disease and has an adverse prognosis. MicroRNAs (miRNAs) that accumulate during the course of cardiac hypertrophy may participate in the process. However, the nature of any interaction between a hypertrophy-specific signaling pathway and aberrant expression of miRNAs remains unclear. In this study, Spague Dawley male rats were treated with transverse aortic constriction (TAC) surgery to mimic pathological hypertrophy. Hearts were isolated from TAC and sham operated rats (n=5 for each group at 5, 10, 15, and 20 days after surgery) for miRNA microarray assay. The miRNAs dysexpressed during hypertrophy were further analyzed using a combination of bioinformatics algorithms in order to predict possible targets. Increased expression of the target genes identified in diverse signaling pathways was also analyzed. Two sets of miRNAs were identified, showing different expression patterns during hypertrophy. Bioinformatics analysis suggested the miRNAs may regulate multiple hypertrophy-specific signaling pathways by targeting the member genes and the interaction of miRNA and mRNA might form a network that leads to cardiac hypertrophy. In addition, the multifold changes in several miRNAs suggested that upregulation of rno-miR-331*, rno-miR-3596b, rno-miR-3557-5p and downregulation of rno-miR-10a, miR-221, miR-190, miR-451 could be seen as biomarkers of prognosis in clinical therapy of heart failure. This study described, for the first time, a potential mechanism of cardiac hypertrophy involving multiple signaling pathways that control up- and downregulation of miRNAs. It represents a first step in the systematic discovery of miRNA function in cardiovascular hypertrophy.

Lymphogenous cyst-vein shunt in the management of chylothorax and chylorrhea

A 36 year-old woman developed marked lymphedema and chylous cysts of the lower abdominal wall, groin, labia, accompanied by chylorrhea. After cyst excision and transplantation of the greater omentum, a left chylothorax occurred. After thoracic duct ligation and left pleurodesis, pleural effusion recurred and worsened. Lymphangioscintigraphy and conventional lymphography suggested that undrained enlarged retroperitoneal lymphatics in the right iliac fossa had disrupted and lymph had leaked into the left chest from the right iliac fossa. Treatment by a lymphatic cyst-vein anastomosis redirected excess chylous lymph into the blood circulation and chylothorax initially remitted. Several years later with recurrence of chylorrhea, the anastomosis was found to be occluded. After a second operative connection between a lymphogenous cyst and the greater saphenous vein, chylorrhea subsided and chylothorax has remitted for more than 4 years.

[Study on the relationship between PMI and the concentration of zincum and nickel in the vitreous humor of rabbit after death]

OBJECTIVE

To seek a exact method of estimating postmortem interval (PMI).

METHODS

This study detected the concentration of zincum(Zn) and nickel(Ni) in vitreous humor of rabbit at hour 96 after death and explored the relationship between their concentration and PMI using a method ICP-MS.

RESULTS

The concentration of Zn and Ni in vitreous humor of rabbit at hour 24 after death were related to PMI significantly; The formulae of the relationship between PMI and Zn concentrations is y = 0.1404x2 - 1.3351x + 3.8298 (within 24 h; R2 = 0.9202). The formula of the relationship between PMI and Ni concentrations is y = 0.0043x2 - 0.0596x + 0.2665(within 24 h; R2 = 0.9103).

CONCLUSION

The concentration of Zn and Ni in vitreous humor of rabbit may be a reference indicator to estimate early PMI.

Covalent modification of glassy carbon electrodes with beta-alanine for voltammetric separation of dopamine and ascorbic acid

beta-Alanine was covalently grafted on a glassy carbon electrode (GCE) by amine cation radical formation in the electrooxidation process of the amino-containing compound. X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) proved the immobilization of beta-alanine monolayer on GCE. The electrode shows strong electrocatalytic functions to dopamine (DA) and ascorbic acid (AA), reducing the overpotentials by 0.20 V and 0.23 V, respectively. Due to its different catalytic effects toward DA and AA, the modified electrode resolved the overlapping voltammetric responses of DA and AA into two well-defined voltammetric peaks by CV or differential pulse voltammetry (DPV), which can be used for the simultaneous determination of these species in a mixture. The catalytic peak current obtained from DPV was linearly related to DA and AA concentrations in the ranges of 4.0 x 10(-6)-5.0 x 10(-4) mol/L and 2.0 x 10(-5)-6.0 x 10(-3) mol/L with correlation coefficients of 0.997 and 0.995, respectively. The detection limits (3 sigma) for DA and AA were 2.4 x 10(-6) mol/L and 1.2 x 10(-5) mol/L, respectively. The electrode shows good sensitivity, selectivity and stability, and has been applied to the determination of DA and AA simultaneously in samples with satisfactory results.

[Study on the relationship between postmortem interval and the change of absorbance in vitreous humor of rabbit after death]

OBJECTIVE

To seek a exact method of estimating Postmortem interval (PMI).

METHODS

This study was preformed to investigate the relationship between postmortem interval and absorbance in vitreous humor of rabbit after death. The absorbance in vitreous humor of 48 rabbits after death were investigated with Model 754 spectrophotometer in apt wavelength (420 nm).

RESULTS

There exists positive linear regression association between postmortem interval (Y) and absorbance in vitreous humor (X) (r = 0.98327, P < 0.05), during rabbits after death 0 to 72 hours. The formula of linear regression is Y = 453.30 X + 0.75 (Y = postmortem interval = PMI, X = absorbance in vitreous humor).

CONCLUSION

The absorbance in vitreous humor can be as reference indicator to estimate PMI within hour 72.

Long-lasting chemiluminescence of luminol on electrochemically pre-oxidized platinum electrodes in NaOH solution

A long-lasting bright chemiluminescence (CL) of luminol was generated at polycrystalline platinum electrodes with open circuit. The CL can last for several hours with the presence of O(2) in the solution when the electrode was preoxidized at potentials more positive than 1.10 V vs. SCE. The effects of the varieties of solution conditions and surface states of the electrode on the CL intensity and the interfacial potential of the electrode were investigated. It was proposed that PtO was generated at the pre-oxidized potentials and played a role of catalyst of luminol oxidation for generating the CL. The redox couple of PtO/Pt(active) at the electrode surface was maintained in the presence of O(2) and luminol, and generated the interfacial potential more positive than 140 mV. Mathematical treatment of the reaction mechanism was conducted, which led to an approximated expression of a steady CL intensity (I(CL)) as a function of the pre-polarization potential (E( h)) and time (tau( h)) of the electrode. An empirical equation, (I(CL))(4/3) = 3480(-1 + 0.82E( h) + 0.037 ln tau( h)), was estimated from the experimental data.

Scattering in twin-cavity narrow-band interference filters illuminated by a monochromatic beam

The scattering behavior of the all-dielectric twin-cavity narrow-band interference filter is studied both in theory and in experiment in two cases, l(1) = l(2) and l (1) not equal l(2), where l(1) and l(2) are the optical thicknesses of the two cavities. It has been shown that the scattering properties are determined mainly by the spacers in which the electric-field intensities are large because of the presence of large standing-wave fields. The scattered light cones are found on both sides of the filter illuminated by a monochromatic light of which the wavelength (lambda(L)) is shorter than the peak wavelength (lambda(0)?) of the filter. The scattering angle of each cone is equal to the tilted angle of the filter when the peak wavelength of the filter shifts to the illumination wavelength. For the case l(1) not equal l(2), the distributions of the scattered light on both sides of the filter are quite different. The analytical calculations are in good agreement with experimental results. The possible applications of scattering in the twin-cavity filter in determining the bandwidth of the peak transmittance and the optical thicknesses of two spacers are addressed.

Urinary creatinine-skeletal muscle mass method: a prediction equation based on computerized axial tomography

A classic body composition method is estimation of total body skeletal muscle mass (SM, kg) from 24 h urinary creatinine excretion (Cr, g). Two types of prediction equations were suggested: one assumes a constant SM/Cr ratio; and the other assumes a highly variable SM/Cr ratio. We explored these two extreme possibilities by measuring SM with whole-body computerized axial tomography and collecting Cr during meat-free dietary conditions in 12 healthy young men. Prediction equations were developed in the men that fit these two equation types, SM = 21.8 x Cr (SD and CV of SM/Cr ratio, 1.3 kg and 6.0%, respectively) and SM = 18.9 x Cr + 4.1 (r = 0.92, p = 2.55 x 10(-5), and SEE = 1.9 kg). The validity of each model is reviewed. This is the first investigation of Cr-SM method using modern techniques for quantifying total body SM mass.

Polypoid lesions of the gallbladder: diagnosis and indications for surgery

One hundred and eighty-two patients with an ultrasonographic and/or pathological diagnosis of polypoid lesions of the gallbladder (PLG) were reviewed to determine the reliability of ultrasonography in the diagnosis of PLG and the indications for operation in this disease. Of the 182 patients operated on, PLG were demonstrated by the gross appearance of the resected gallbladder in 172. Histologically benign lesions were present in 159 gallbladders and malignant lesions in 13. Cholesterol polyps accounted for most benign PLG. The sensitivity of ultrasonography in detecting PLG was 90.1 per cent, significantly higher than that of oral cholecystography, computed tomography or endoscopic retrograde cholangiopancreatography (P less than 0.01). The specificity of ultrasonography in the diagnosis of PLG was 93.9 per cent. Therefore, ultrasonography is a highly sensitive method for investigating PLG, and the preoperative diagnosis of PLG in this unit has now become entirely dependent on this technique. The size and number of PLG, the presence of gallstones and the patient's age all correlate with the nature of PLG, and these features are helpful in differentiating malignant from benign lesions before operation. Surgical treatment is indicated when PLG exceed 1.0 cm in diameter, when PLG are single in number, when PLG are associated with gallstones, when patients with PLG are over the age of 50 years, or when clinical symptoms of PLG are apparent.

Reliability of ultrasonography in diagnosis of biliary lithiasis

Preoperative B-mode ultrasonograms of the biliary system in 302 patients with cholelithiasis confirmed operatively between March 1981 and December 1986 were analyzed retrospectively in contrast to the operative findings. The results showed that during 1985-1986 the sensitivity of ultrasonography (US) to detect stones in gallbladder (GB), extrahepatic bile duct (EHD) and intrahepatic bile duct (IHD) was 98.4%, 68.2% and 82.4% respectively, each was much higher than its counterpart during the periods 1981-1982 and 1983-1984 (P less than 0.01). The specificity of US in detecting GB, EHD and IHD stones was all over 90% during the latter two years. The observations made in the present study suggest that the accuracy of US has risen so significantly that it should be used as the first modality in diagnosing cholelithiasis, particularly cholecystolithiasis. It, however, should be supplemented with such tests as oral cholecystography, intravenous cholangiography, percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP) to establish a correct diagnosis when its interpretation is equivocal.

[Angiographic studies in osteoradionecrosis of the jaw]

91 angiographical studies have been performed in 25 animal models (dogs) of ORN. Summarized from the results, the following conclusions are reached: a general rule existed between bone lesion and blood vessel damage--the destruction of the bone was more severe than that of the middle-sized arteries, the damage of middle-sized arteries was more severe than that of arterioles, and local proliferation of arterioles accompanied with bone lesions. Therefore, damage of the arterioles is not the main pathological findings of jaw ORN, the nature of ORN is direct injuries of radiation rays to bone tissues.

[99mTc-MDP bone scintigraph in the diagnosis of experimental osteoradionecrosis (ORN) of the jaw]

Controlled studying findings from 62 radionuclide scintigraphic and X-ray photographic examinations of the same stage in the experimental animals indicated. The diagnosis of ORN could hardly be established while bone scintigraphic examination is negative, but it is recommended that ORN mostly exists if scintigraphic result is positive. The grading of bone scanning based on the difference of radionuclide concentration in diseased area offered a reference for treatment. Measuring and calculating both examination pictures, we put forward a method to quantitatively determine the limits of lesions. The facts showed by bone scanning that blood supply was rich and metabolism was vigorous in diseased area of ORN presented a new object for research on fundamental theory.

[Clinical observation of osteoradionecrosis (ORN) of the jaw]

Clinical observations and investigations on 48 patients treated in a 15-year period were presented. From the studying results of radionuclide scintigraphic examination we raised a new opinion that the bone in diseased area had its rich blood supply and presented an active metabolism during certain stage. Findings from clinical and radiological examinations indicated that the teeth factors in pathogenesis of ORN had no special significance. Our patients received mainly the supervoltage or megavoltage radiotherapy, so that the symptoms and clinical manifestations were milder than those seen previously. The treatment results of all cases suggest that mandibular resection be the best treatment method for ORN and hyperbaric oxygen therapy has no obvious effects.