[Application of augmented reality and mixed reality navigation technology in laparoscopic limited right hepatectomy].

Objective: To investigate the application effect of augmented reality and mixed reality navigation technology in three-dimensional(3D) laparoscopic narrow right hepatectomy(LRH). Methods: A retrospective analysis was performed on the clinical data of 5 patients with hepatic malignancy admitted to the First Department of Hepatobiliary Surgery,Zhujiang Hospital,Southern Medical University from September 2020 to June 2021,all of whom were males,aged from 42 to 74 years.Preoperative evaluation was performed using the self-developed 3D abdominal medical image visualization system; if all the 5 patients were to receive right hemihepatectomy,the remnant liver volume would be insufficient,so LRH were planned.During the operation,the independently developed 3D laparoscopic augmented reality and mixed reality surgical navigation system was used to perform real-time multi-modal image fusion and interaction between the preoperative 3D model and 3D laparoscopic scene.Meanwhile,intraoperative ultrasound assisted indocyanine green fluorescence was used to determine the surgical path.In this way,the LRH under the guidance of augmented reality and mixed reality navigation was completed.The predicted liver resection volume was evaluated before surgery,actual resected liver volume,surgical indicators and postoperative complications were analyzed. Results: All the 5 patients completed LRH under the guidance of augmented reality and mixed reality navigation technology,with no conversion to laparotomy.The median operative time was 300 minutes(range:270 to 360 minutes),no intraoperative blood transfusion was performed,and the median postoperative hospital stay was 8 days(range:7 to 9 days).There were no perioperative deaths,or postoperative complications such as liver failure,bleeding,or biliary fistula. Conclusion: For patients who need to undergo LRH,the use of augmented and mixed reality navigation technology can safely and effectively guide the implementation of surgery,retain more functional liver volume,improve surgical safety,and reduce postoperative complications.

[Three-dimensional visual assessment and virtual reality study of centrally located hepatocellular carcinoma on the axis of blood vessels].

Objective: To explore a novel method for preoperative precision assessment of centrally located hepatocellular carcinoma(HCC) with blood vessel as axis based on three-dimensional(3D) visualization and virtual reality(VR) technology and its application values. Methods: High-quality thin-layer enhanced CT data were collected from 20 patients with centrally located HCC who treated at First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University from March 2017 to August 2018 diagnosed by preoperative examination. There were 18 males and 2 females, aged 28 to 69 years, all of Child-Pugh grade A. First of all, 3D reconstruction was performed by a 3D visualization software; then, the reconstructed 3D image was imported into VR development engine for VR research; afterwards, the analysis and evaluation system with blood vessel as axis was established based on 3D visualization classification of centrally located HCC; therefore, the relationship of the tumor to its major peripheral blood vessels was accurately judged and the surgical planning was formulated. Two images were brought into the operating room for navigation in surgery. The assessments results of preoperative data (CT and (or) MRI) and three-dimensional visualization of blood vessels in VR environment were compared; the values of the preoperative and postoperative hemoglobin, serum albumin and bilirubin were recorded and compared. Chi-square test, t-test and non-parametric test were used for the analysis of counting data, continuous measurement data and non-normal distribution measurement data, respectively. Results: 3D visualization modeling was completed in all of the 20 patients with centrally located HCC. According to the results of 3D visualization classification of centrally located HCC, there were 3 cases of type Ⅰ,1 case of type Ⅱ,4 cases of type Ⅲ,7 cases of type Ⅳ and 5 cases of type Ⅴ; according to the assessment and classification based on blood vessel as the axis, there were 6 cases of type Ⅰa,2 cases of type Ⅰb,2 cases of type Ⅱa,9 cases of type Ⅱb and 1 case of type Ⅱc. All patients underwent successful resection of tumor under the guidance of 3D visualization and VR technology. There were 15 cases whose assessment results based on preoperative CT/MRI were consistent with intraoperative findings, with a coincidence rate of 75.0%(15/20); while in VR environment, the assessment results of 3D visualization with blood vessel as axis were all consistent with the intraoperative findings, with coincidence rate of 100%(20/20). There was a statistically significant difference between the groups (χ(2)=5.714, P=0.017). There was no red blood cell transfusion in all patients during the operation. The preoperative hemoglobin was (128.8±14.9)g/L, and it was (119.8±12.5)g/L on postoperative day 1. There was no significant difference between these two sets of data (t=2.07, P=0.054). No death during the perioperative period and no complications such as hepatic failure, hemorrhage and biliary fistula after operation occurred. Conclusion: Preoperative evaluation based on 3D visualization and VR technology with blood vessel as the axis has significant clinical value for preoperative planning and surgical navigation of centrally located HCC.

[Application of augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging in laparoscopic hepatectomy].

Objective: To study the application value of augmented-reality (AR) surgical navigation technology combined with indocyanine green (ICG) molecular fluorescence imaging in three-dimensional (3D) laparoscopic hepatectomy. Methods: The clinical data of forty-eight patients who had undergone 3D laparoscopic hepatectomy for hepatocellular carcinoma at First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University from January 2018 to April 2019 were retrospectively analyzed.The patients were divided into two groups: the group of 3D laparoscopic hepatectomy navigated by augment reality technology combined with ICG molecular fluorescence imaging (Group A) , and group of conventional 3D laparoscopic hepatectomy (Group B) . Patients in Group A (n=23) underwent 3D laparoscopic hepatectomy using augmented-reality technology combined with ICG molecular fluorescence imaging. In this group, the self-developed three-dimensional laparoscopic augmented-reality surgical navigation system (No. 2018SR840555) was operated to project the preoperative three-dimensional model to the surgical field, and the use of this system in combination with ICG molecular fluorescence imaging navigated laparoscopic hepatectomy. No surgical navigation technology was applied in Group B (n=25) . All patients signed the informed consent, which were in accordance with the requirements of medical ethics (Ethics No.: 2018-GDYK-003) . The preoperative data, surgical indicators and postoperative complications between the two groups were compared and analyzed. Results: The median amount of intraoperative blood loss of Group A was 250 (200) ml (M (Q(R)) ) , which was significantly lower than that of Group B (300 (150) ml) (Z=-2.307, P=0.021) .The transfusion rate of Group A was 13.0% (3/23) , which was significantly lower than that of Group B (40.0%, 10/25) (χ(2)=4.408, P=0.036) .The median postoperative hospitalization time of Group A was 8 (2) d, which was significantly shorter than that of Group B (11 (6.5) d) (Z=-2.694, P=0.007) . There were no serious complications and perioperative death in both groups.The incidence of postoperative complications in Group A was 17.4% (4/23) , which was not significantly different from that in group B (28%, 7/25) (χ(2)=0.763, P=0.382) . Conclusion: Augmented-reality surgical navigation technology combined with ICG molecular fluorescence imaging has better effect in 3D laparoscopic hepatectomy.

Semi-automatic volume measurement for orbital fat and total extraocular muscles based on Cube FSE-flex sequence in patients with thyroid-associated ophthalmopathy.

AIM: To investigate the accuracy of two semi-automatic segmentation measurements based on magnetic resonance imaging (MRI) three-dimensional (3D) Cube fast spin echo (FSE)-flex sequence in phantoms, and to evaluate the feasibility of determining the volumetric alterations of orbital fat (OF) and total extraocular muscles (TEM) in patients with thyroid-associated ophthalmopathy (TAO) by semi-automatic segmentation. MATERIALS AND METHODS: Forty-four fatty (n=22) and lean (n=22) phantoms were scanned by using Cube FSE-flex sequence with a 3 T MRI system. Their volumes were measured by manual segmentation (MS) and two semi-automatic segmentation algorithms (regional growing [RG], multi-dimensional threshold [MDT]). Pearson correlation and Bland-Altman analysis were used to evaluate the measuring accuracy of MS, RG, and MDT in phantoms as compared with the true volume. Then, OF and TEM volumes of 15 TAO patients and 15 normal controls were measured using MDT. Paired-sample t-tests were used to compare the volumes and volume ratios of different orbital tissues between TAO patients and controls. RESULTS: Each segmentation (MS RG, MDT) has a significant correlation (p<0.01) with true volume. There was a minimal bias for MS, and a stronger agreement between MDT and the true volume than RG and the true volume both in fatty and lean phantoms. The reproducibility of Cube FSE-flex determined MDT was adequate. The volumetric ratios of OF/globe (p<0.01), TEM/globe (p<0.01), whole orbit/globe (p<0.01) and bone orbit/globe (p<0.01) were significantly greater in TAO patients than those in healthy controls. CONCLUSION: MRI Cube FSE-flex determined MDT is a relatively accurate semi-automatic segmentation that can be used to evaluate OF and TEM volumes in clinic.

Relation between therapy options for Graves' disease and the course of Graves' ophthalmopathy: a systematic review and meta-analysis.

BACKGROUND: The relation between therapy options for Graves' disease (GD) and the course of Graves' ophthalmopathy (GO) are still controversial. Our aim was to compare the occurrence of development or worsening of GO in patients who were treated with antithyroid drugs (ATDs) or radioactive iodine (RAI) or thyroidectomy (TX). METHODS: We conducted a comprehensive search of the Embase and PubMed database. Odds ratio (OR) was used as a measure of the effect of therapy options for GD on the risk of development or worsening of GO. The analysis was further stratified by factors that could affect the treatment effects. RESULTS: Nine trials involving 1773 patients were included. RAI therapy showed a significant effect on the risk of development or worsening GO compared with ATD (OR 2.25; 95 % CI 1.61-3.14; P < 0.00001). Glucocorticoid prophylaxis was effective in preventing GO development or worsening (0.40; 0.23-0.68; P = 0.002); especially for patients with preexisting GO (0.41; 0.23-0.73; P = 0.002). At 3 months, showed GO to be improved in 17 TX and 21 total thyroid ablation (TTA) patients, with no significant difference between the two groups; between 6 and 12 months, TTA did show significant beneficial effect on the improvement of GO (6.02; 2.80-12.96; P < 0.00001); GO was found to be inactive in a significantly higher percentage of patients in the TTA (2.17; 1.04-4.52; P = 0.04). CONCLUSION: Radioiodine therapy is a significant risk factor for development or worsening of GO in GD. But GO progression can be prevented by prophylactic glucocorticoids in patients with preexisting GO. Compared with TX alone, TTA induces an earlier and steadier GO improvement in patients with mild to moderate-severe and active GO. Whether this is sufficient to offer TTA to patients needs further investigation.

[Analysis of intrahepatic Glisson's sheath vascular disconnection approach for anatomical hepatectomy by three-dimensional laparoscope].

OBJECTIVE: To investigate the clinical value of the intrahepatic Glisson's sheath vascular disconnection approach for anatomical hepatectomy by three-dimensional(3D) laparoscope. METHODS: Twenty-two patients(11 liver cancer and 11 benign diseases)underwent hepatectomy in Zhujiang Hospital, Southern Medical University from November 2013 to March 2015 were involved. All patients were performed anatomical hepatectomy by 3D laparoscope with the intrahepatic Glisson's sheath vascular disconnection approach.The anatomical time of first hepatic portal, operation time, intraoperative bleeding, postoperation hospitalization and the complication incidences were observed. RESULTS: All the 22 cases were performed successfully with the intrahepatic Glisson's sheath vascular disconnection and the anatomic hepatectomy. The anatomical time of first hepatic portal, operation time, intraoperative bleeding, the postoperation hospitalization duration and complication incidence rate were(43±14) minutes(22-74 minutes), (295±89) minutes(105-480 minutes), (546±390) ml (50-1 500 ml), (9.8±2.8) days(5-16 days) and 18.2%(4/22)in 22 patients, respectively. There was no death. CONCLUSIONS: With the help of 3D laparoscope, the anatomy of Glisson pedicle could perform precisely and the dissection of vessels would be easy and accuracy. The 3D laparoscope is feasible for performing the anatomical hepatectomy.

[Application of indocyanine green-fluorescent imaging technique in planning resection line and real-time surgical navigation in small hepatocellular carcinoma].

Objective: To explore the value of near-infrared technology guided by indolecyanine green(ICG) in planning resection line and real-time surgical navigation in small liver cancer. Methods: From March to September 2015, 11 patients with hepatic tumors received hepatectomy were treated in First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University.There were 5 male and 6 female patients with average age of (55±10)years (range 39-70 years). Among whom, there were 9 cases with hepatocellular carcinoma and 2 cases with colorectal cancer. A near-infrared light camera system was used to detect the liver surfaces before resection, and to plan resection line and surgical specimens. A student's t test was used to compare continuous parametric variables. Results: The ICG-fluorescent imaging and histological examination had been used in the 15 lesions of the 11 patients. Among the 15 lesions, 7 lesions were detected by visual inspections, palpation and ICG-fluorescent imaging, 6 lesions were identified only by ICG-fluorescent imaging, 2 lesions were detected only by ICG-fluorescent imaging after resection.Results of pathologic examination indicated that the total fluorescent type include 5 well differentiated hepatocellular carcinoma and 2 cirrhotic nodule; the partial fluorescent type include 3 moderately differentiated hepatocellular carcinomas and 1 well differentiated hepatocellular carcinomas; the rim fluorescent type included 2 liver metastatic carcinoma and 2 poorly differentiated hepatocellular carcinomas. The average diameter of the tumor size measured by CT was (1.7±0.2)cm, while the average diameter measured by ICG-fluorescent imaging was (1.7±0.3)cm(t=-0.188, P>0.05). Conclusion: Near-infrared technology guided by ICG has important value in planning resection line and real-time surgical navigation in small liver cancer.

[The construction of three-dimensional visualization platform and its application in diagnosis and treatment for hilar cholangiocarcinoma].

OBJECTIVE: To explore the construction and clinical efficacy of three-dimensional(3D) visualization platform about diagnosis and treatment of hilar cholangiocarcinoma. METHODS: From January 2009 to December 2015, a total of 32 patients with hilarcholangiocarcinoma treated in Zhujiang Hospital of Southern Medical University were analyzed.There were 20 male and 12 female patients aged from 40 to 85 years. Bismuth-Corlette 3D visualization type: 2 cases with type Ⅰ, 5 cases with type Ⅱ, 10 cases with type Ⅲa, 11 cases with type Ⅲb, 4 cases with type Ⅳ.Among 32 cases, there were 5 cases who were established liver 3D printing models to guide intraoperative real-time navigation.The clinical effect of this platform was evaluated by the operation time, intraoperative blood loss, laboratory test and postoperative complications.The 3D visualization platform consists of the preoperative surgical planning with the aid of virtual 3D reconstruction technology and intraoperative real-time navigation with 3D printing models. RESULTS: The liver 3D models for all patients were constructed successfully, they could clearly show intrahepatic pipeline, size and location of tumors, relationship between tumor and intrahepatic pipeline.The 3D printing models could accomplish real-time intraoperative navigation surgery with strong stereoscopic sense.According to Bismuth classification 3D visualization type, 2 patients with type Ⅰ received local excision of tumor and choledochojejunostomy; 5 patients with type Ⅱ received resection of segment Ⅰ, Ⅳb and partial Ⅴ combined with choledochojejunostomy; 10 patients with type Ⅲa received right semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 11 cases with type Ⅲb received left semi-hepatectomy combined with resection of segment Ⅰ and choledochojejunostomy; 4 cases with type Ⅳ received resection of segment Ⅳb and Ⅴ combined with choledochojejunostomy.The operation time was 270-660 minutes; the mean intraoperative blood loss was 588 ml; the mean postoperative hospital stay was 25 days.The bilirubin level three day after operation was 233 µmol/L.There was 1 case presented biliary fistula and cured by conservative treatment; there was no incision infection, no liver failure and no perioperative deaths occurred. CONCLUSION: The 3D visualization is valuable for optimizing the operation scheme preoperatively and navigating surgery accurately intraoperatively in real-time which may improve the precision of the operation and achieve better the recovery.

[A comparative study of lacrimal magnetic resonance hydrography and lacrimal endoscopy examination in the diagnosis and treatment of lacrimal duct obstructive diseases].

OBJECTIVE: To evaluate the diagnostic value and treatment guidance of lacrimal magnetic resonance hydrography (LMRH) and lacrimal endoscopy examination in lacrimal duct obstruction. METHODS: A retrospective analysis of clinical and imaging data of 59 patients with epiphora who had LMRH examination in Tongji Hospital during June 2013 and January 2014. Multiplanar reconstruction (MPR) and maximum intensity projection (MIP) were used to process the three dimensions T2-weighted images (T2WI). The size of lacrimal sac, lacrimal mucosal lesions and the obstructed plane of nasolacrimal duct were observed. The lacrimal irrigation results were used as gold standard. The sensitivity, specificity, accuracy of LMRH in diagnosis of lacrimal duct obstructive diseases and the consistency between the two methods were analyzed. In addition, 22 cases had lacrimal endoscopy examination in less than half month after MRD. The results of lacrimal endoscopy were compared with LMRH images. The treatment method was made according to the results of LMRH and lacrimal endoscopy. RESULTS: According to the results of lacrimal irrigation, among 78 eyes of 59 patients, 2 eyes were diagnosed as lacrimal canalicular obstruction (2.6%, 2/78), 8 eyes were diagnosed as nasolacrimal duct stenosis (10.3%, 8/78), 24 eyes were diagnosed as nasolacrimal duct obstruction (30.8%, 24/78), 44 eyes were diagnosed as nasolacrimal duct obstruction accompanied with chronic dacryocystitis (56.4%, 44/78). The other 40 eyes were negative controls. LMRH had a high degree of consistency with lacrimal irrigation in diagnosis of lacrimal duct obstructive diseases. The value of Kappa was 0.963 (P= 0.026). The sensitivity of MRD in diagnosis of lacrimal duct obstructive diseases was 97.4%, the specificity was 100%, the accuracy was 98.3%, the positive predictive value was 100% and the negative predictive value was 95.2% . According to 40 eyes of the control group, the mean value of the maximum cross-sectional area of the lacrimal sac was: (10.9 ± 0.4) mm(2). Twenty-two eyes underwent lacrimal endoscopy examination and the endoscopic findings were consistent with LMRH diagnosis. The lesions in the lacrimal duct displayed more clearly and intuitively than the LMRH, while LMRH had its unique advantages in showing the size of lacrimal sac, the mucosal thickness of lacrimal duct, large foreign bodies and lesions around the lacrimal duct. According to the results of LMRH and lacrimal endoscopy, 2 eyes of canalicular obstruction, 8 eyes of nasolacrimal duct stenosis, 20 eyes of nasolacrimal duct obstruction underwent lacrimal probing and stent implantation. Four eyes of nasolacrimal duct obstruction had drug treatment under lacrimal endoscopy. Thirty-eight eyes of chronic dacryocystitis underwent endonasal dacryocystorhinostomy. The other 6 eyes of chronic dacryocystitis underwent stent removal combined with endonasal dacryocystorhinostomy. CONCLUSIONS: LMRH is a noninvasive and reliable method to examine the lacrimal duct obstruction. It can better display the size of lacrimal sac, lacrimal mucosal thickness and surrounding soft tissues of lacrimal duct. It is also a good complementary method of lacrimal endoscopy and has guiding significance for individualized treatment in patients with lacrimal duct obstruction.

Study on the relation of the solar coronal rotation with magnetic field structures.

Daily solar spectral irradiances (SSIs) at the spectral intervals 1-40, 116-264 and 950-1600 nm and four categories of solar small-scale magnetic elements ([Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) are used to study the temporal variation of coronal rotation and investigate the relation of the coronal rotation with magnetic field structures through continuous wavelet transform and Pearson correlation analysis. The results reveal the contributions of different magnetic structures to the temporal variation of the rotation for the coronal atmosphere during different phases of the solar cycle. During the solar maximum, the temporal variation of rotation for the coronal plasma atmosphere is mainly dominated by the small-scale magnetic elements of [Formula: see text]; whereas during the epochs of the relatively weak solar activity, it is controlled by the joint effect of the small-scale magnetic elements of both [Formula: see text] and [Formula: see text]. The weaker the solar activity, the stronger the effect of [Formula: see text] would be. Furthermore, this study presents an explanation for the inconsistent results for the coronal rotation issue among the previous studies, and also reveals the reason why the coronal atmosphere rotates faster than the lower photosphere.

Response to the first wave of pandemic (H1N1) 2009: experiences and lessons learnt from China.

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.

Coherent energy exchange between components of a vector soliton in fiber lasers.

We report on the experimental evidence of four wave mixing (FWM) between the two polarization components of a vector soliton formed in a passively mode-locked fiber laser. Extra spectral sidebands with out-of-phase intensity variation between the polarization resolved soliton spectra was firstly observed, which was identified to be caused by the energy exchange between the two soliton polarization components. Other features of the FWM spectral sidebands and the soliton internal FWM were also experimentally investigated and numerically confirmed.

Soliton trapping in fiber lasers.

We report on the soliton trapping in a fiber ring laser modelocked with a SESAM. It was observed that solitons along the two orthogonal polarization directions of the cavity with fairly large difference in central frequency and energy could be coupled together to form a group velocity locked vector soliton. In particular, due to that each of the coupled solitons forms its own soliton sidebands, two sets of soliton sidebands could be observed on the vector soliton spectrum. Numerical simulations have well confirmed the experimental observations.

Treatment of epigastralgia by external application of huweigao at shenque point.

140 cases of epigastralgia were divided into two groups at random. The 100 cases in the treatment group were treated with Huweigao externally applied at Shenque (Ren 8), and the 40 cases in the control group by oral administration of Weinaian capsule. After a one-month treatment, the total symptom-relieving rate and the gastroscopy-proved effective rate were 94.0% and 52.6% respectively in the treatment group, much superior to those in the control group.

Surface characteristics and corrosion properties of selective laser melted Co-Cr dental alloy after porcelain firing.

OBJECTIVE: We examined the surface characteristics and corrosion properties of selective laser melted (SLM) cobalt-chromium (Co-Cr) dental alloys before and after porcelain-fused-to-metal (PFM) firing. METHODS: Samples were manufactured utilizing SLM techniques and control specimens were fabricated using traditional casting methods. The microstructure and surface composition were examined using metallographic microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Corrosion properties were evaluated using electrochemical impedance spectroscopy. Student's t-test was used to evaluate differences in numerical results of electrochemical corrosion tests between SLM and cast specimens before or after PFM firing. The results of electrochemical corrosion tests of the SLM and cast samples before and after firing were analyzed using one-way ANOVA. RESULTS: Although PFM firing altered the microstructure of the SLM specimens, they still exhibited a compact and homogeneous structure, and XPS analysis indicated that there were no significant differences in the surface composition of the specimens after firing. In artificial saliva at pH 5, the Rp value of the SLM specimens was 6.21MΩcm(-2) before firing and 2.84MΩcm(-2) after firing, suggesting there was no significant difference in electrochemical corrosion properties (P>0.05). In artificial saliva at pH 2.5, the Rp value of the SLM group was 4.80MΩcm(-2) before firing and 2.88MΩcm(-2) after firing, again indicating no significant difference in electrochemical corrosion properties (P>0.05). At pH 2.5, there was a significant difference in corrosion behavior between the cast and SLM groups, with the Rp value of the cast group being 0.78MΩcm(-2) vs. 2.88MΩcm(-2) for the SLM group. SIGNIFICANCE: The improved post-firing corrosion resistance of SLM specimens provides further support for their use in prosthodontic applications, as the oral environment may become temporarily acidic following meals.

Surface-enhanced Raman spectral biomarkers correlate with Ankle Brachial Index and characterize leg muscle biochemical composition of patients with peripheral arterial disease.

Peripheral arterial disease (PAD) is characterized by atherosclerotic blockages of the arteries supplying the lower extremities, which cause a progressive accumulation of ischemic injury to the skeletal muscles of the lower limbs. This injury includes altered metabolic processes, damaged organelles, and compromised bioenergetics in the affected muscles. The objective of this study was to explore the association of Raman spectral signatures of muscle biochemistry with the severity of atherosclerosis in the legs as determined by the Ankle Brachial Index (ABI) and clinical presentation. We collected muscle biopsies from the gastrocnemius (calf muscle) of five patients with clinically diagnosed claudication, five patients with clinically diagnosed critical limb ischemia (CLI), and five control patients who did not have PAD. A partial least squares regression (PLSR) model was able to predict patient ABI with a correlation coefficient of 0.99 during training and a correlation coefficient of 0.85 using a full cross-validation. When using the first three PLS factor scores in combination with linear discriminant analysis, the discriminant model was able to correctly classify the control, claudicating, and CLI patients with 100% accuracy, using a full cross-validation procedure. Raman spectroscopy is capable of detecting and measuring unique biochemical signatures of skeletal muscle. These signatures can discriminate control muscles from PAD muscles and correlate with the ABI and clinical presentation of the PAD patient. Raman spectroscopy provides novel spectral biomarkers that may complement existing methods for diagnosis and monitoring treatment of PAD patients.

Assessing the correlates of desired family size in Shaanxi, China.

This exploratory analysis of factors associated with Chinese women's fertility desires uses data on married women between the ages of 18 and 35 who live in Shaanxi Province, China. Analyses using an economic framework found that both rural and urban couples who intended to sign, or who had already signed, the one-child certificate reported wanting significantly fewer children. However, in rural areas (where 80 per cent of the provincial population lives), education level, living arrangements, participation in an arranged marriage, attitudes regarding the ideal age for marriage, and knowledge of the reasons for the government's fertility policies appear to play a relatively larger role in shaping fertility preferences.

PIP: An exploratory factor analysis of the political, cultural, and socioeconomic determinants of Chinese women's fertility desires was conducted. Data were obtained from the 1985 China In-Depth Fertility survey for Shaanxi province among 2370 married women 35 years or younger at the time of the survey. The framework for this analysis was based on Easterlin's theory about demand for children and price and income constraints. Price was measured by response to the one-child certificate, marriage delay due to group pressure, residence in an extended family, and woman's educational level. Traditional cultural influences were measured by residence with husband's parents soon after marriage, arranged marriage, correct identification of the reason for the one-child policy, ideal marriage age, and age difference between spouses. The results confirmed the findings of Whyte and Gu on family size desires of 2 children among Hubei respondents. Shaanxi wives were, however, more likely to report a desire of 0 or 2. Childless women tended to report smaller family size desired than women who already had one child. Urban childless women were more likely to desire a family size of one child than rural childless women: 28.4% versus 5.5%. 28.5% of rural women with at least one child desired a family size of three. Urban women were more likely to have signed a one-child certificate. Urban childless women were more likely to live in an extended family and to have a higher educational level than their counterparts. Tobit maximum likelihood estimation methods were used to examine how price, income, and traditional taste variables affected family size desired. The small sample size of urban childless women yielded weaker relationships. Findings indicate evidence of interactions between residence location, actual number of children, and the 12 variables. One-child certificate acceptance increased the cost of children and lowered desires to have more. Educational level only affected fertility desires among rural women with children. Higher family size desires were associated with a younger ideal marriage age. Smaller family size desires were associated with rural women who knew the reason for the one-child certificate and who lived in extended families. Income measures were insignificant.

Evaluation of decay times in coupled spaces: Bayesian parameter estimation.

Determination of sound decay times in coupled spaces often demands considerable effort. Based on Schroeder's backward integration of room impulse responses, it is often difficult to distinguish different portions of multirate sound energy decay functions. A model-based parameter estimation method, using Bayesian probabilistic inference, proves to be a powerful tool for evaluating decay times. A decay model due to one of the authors [N. Xiang, J. Acoust. Soc. Am. 98, 2112-2121 (1995)] is extended to multirate decay functions. Following a summary of Bayesian model-based parameter estimation, the present paper discusses estimates in terms of both synthesized and measured decay functions. No careful estimation of initial values is required, in contrast to gradient-based approaches. The resulting robust algorithmic estimation of more than one decay time, from experimentally measured decay functions, is clearly superior to the existing nonlinear regression approach.