Energy conservation at an optical temporal boundary.

The temporal boundary appears as a novel phenomenon in a wide range of optical devices and systems, such as the photonic crystal, metamaterials, optical microcavity, and modulator, with a dynamic medium whose refractive index changes across the boundary. However, the validation of electromagnetic energy conservation was considered in violation for the optical temporal boundary traditionally. Here a new energy space-time scheme is proposed for an optical pulse in a medium with the temporal boundary. From the Poynting theory, the electromagnetic energy is investigated based on a one-dimensional model under the assumption of impedance matching. Furthermore, the results demonstrate that a more general conservation of energy is validated in a time domain for the ideal scenario. A new invariant quantity of spatial energy in the optical medium is further obtained. The numerical results are in agreement with the theory of the temporal boundary. The conservative process of energy transportation across the optical temporal boundary is clarified and confirmed.

Anisotropic dependence of light extraction behavior on propagation path in AlGaN-based deep-ultraviolet light-emitting diodes.

The anisotropic extraction dependence of polarized light on propagation path in AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) is investigated by simulations and photoluminescence (PL) measurements. Theoretical calculations based on k⋅p approximation and Monte Carol ray tracing indicate that there are two kinds of polarized sources with different angular distributions in ~280 nm AlGaN-based LEDs, s-polarized (spherical-shaped) and p-polarized (dumbbell-shaped) sources, which have different extraction behaviors. It is found that the total light extraction intensities are improved with decreasing the propagation path, and the lateral surface extraction gradually becomes dominant. Moreover, the extraction intensity of s-polarized light improves more than that of p-polarized light when the propagation path decreases, leading to a greater polarization degree. Polarization-resolved PL measurements show that the polarization degree of extracted light from lateral facet of the AlGaN multiple quantum well sample can be enhanced from 1% to 17% as the average propagation path reduces by 0.6 mm, which is consistent with the simulation results of the anisotropic dependence of light extraction on propagation path. Our results are significant for understanding and modulating the anisotropic extraction behavior of polarized light to realize high efficiency AlGaN-based DUV LEDs.

[A study on measles and rubella antibody level in 319 pairs of mothers and infants in Songjiang District of Shanghai].

Objective: To explore serum levels of measles and rubella IgG antibodies among mothers and infants. Methods: According to the inclusion and exclusion criteria, we selected 319 puerperae and their infants in maternal hospitals of Songjiang district November 2016 to February 2017, venous blood were collected and serum measles and rubella IgG antibodies were measured using ELISA. To study the correlation between the level of measles and rubella antibodies in infants and mothers' by using the Spearman's correlation analysis. Results: The age at delivery was (29.71±4.25) years old; and the gestational age at delivery was (39.06±1.30) weeks. The positive rate and protection rate of measles antibody in puerperae were 82.5% (243/319) and 43.3% (135/319), the GMC [M (QR)] was 655.74 (251.21-1 299.02) mIU/ml. The positive rate of rubella antibody in puerperae was 61.1% (195/319), the GMC [M (QR)] was 31.34 (11.65-73.61) IU/ml. The positive rate and protection rate of measles antibody in infants were 84.1% (270/321) and 46.1% (148/321), the GMC [M (QR)] was 665.07 (279.63-1 544.07) mIU/ml. The positive rate of rubella antibody in infants was 69.5% (223/321), the GMC [M (QR)] was 40.30 (16.12-98.48) IU/ml. There was statistical difference in measles (Z=-14.64, P<0.001) and rubella (Z=-8.66, P<0.001) antibody levels between mothers and infants. There was positive correlation in measles (r=0.76, P<0.001) and rubella (r=0.86, P<0.001) antibody level between mothers and infants. Conclusion: The maternal antibody of measles and rubella had a concentration effect. The level of measles and rubella antibodies in the infants was higher than that in the mothers' and increased with the increase of the level of measles and rubella antibodies in the mothers.

[Clinical observation of apatinib mesylate for the treatment of multi-drug resistant advanced breast cancer].

Objective: To assess the clinical efficacy and adverse outcomes of apatinib mesylate for the treatment of multi-drug resistant advanced breast cancer. Methods: A total of 24 patients with multi-drug-resistant advanced breast cancer who underwent apatinib mesylate treatment were retrospectively analyzed at the Diagnosis and Treatment Center for Breast Cancer of Henan Cancer Hospital. Patients were reviewed every 4 weeks after initial treatment and then every 8 weeks after stable disease. Objective response rate (ORR), progression free survival (PFS), overall survival (OS) , toxicity and adverse outcomes of apatinib mesylate treatment were evaluated by imaging examinations. Results: Totally, 24 patients received apatinib mesylate at a dose of 500 mg QD. Out of the 24 patients treated, complete remission (CR) occurred in none of the patients, partial remission (PR) in 10 cases, stable disease (SD) in 10 cases, progressive disease (PD) in 4 cases, and drug with drawal in 2 cases due to adverse outcomes. Treatment with apatinib mesylate resulted in an ORR of 41.7% (10/24), disease control rate (DCR) of 83.3%, PFS of 4.7 months, and OS of 8.0 months. Adverse outcomes included proteinuria, high blood pressure, fatigue, hand-foot skin reaction (HFSR), hyperbilirubinemia, leukopenia, hair/skin pigmentation decreased. Most of the adverse events were tolerable and can be controlled after symptomatic management. Conclusions: Single-agent apatinib mesylate demonstrated the good short-term efficacy for multi-drug resistant advanced breast cancer in patients who previously underwent multiple line treatment failures. Adverse effects were controllable after symptomatic management. Treatment with apatinib mesylate maybe a viable option when other treatment modalities failed.

[The effect of follicular fluid from patients with endometriosis, follicle stimulating hormone and bone morphogenetic protein 15 on the proliferation and progesterone secretion of granular cells].

Objective: The study was designed to evaluate the effect of follicular fluid from patients with endometriosis, follicle stimulating hormone (FSH), bone morphogenetic protein 15 (BMP-15) on the proliferation and progesterone secretion of human luteinized granular cells in vitro. Methods: Cumulus granulosa cells were collected from the patients who underwent in vitro fertilization and embryo transfer (IVF-ET) ovulation due to tubal or male factor infertility on the day of the retrieval. The cells in the control group were cultured with complete medium of DMEM/F-12, an extra of FSH at a dose of 12 µg/L was added in the FSH group, an extra of BMP-15 at a dose of 6 µg/L was added to the BMP-15 group, an extra of 5% of the follicular fluid from the patients with tubal or male factor infertility was added to the tubal group, an extra of 5% of the follicular fluid from the patients with endometriosis infertility was added to the endometriosis group, an extra of 5% of the follicular fluid from the patients with endometriosis infertility plus FSH at a dose of 12 µg/L were added to the endometriosis plus FSH group, and an extra of 5% of the follicular fluid from the patients with endometriosis infertility plus BMP-15 at a dose of 6 µg/L were added to the endometriosis plus BMP-15 group. Hemacytometer counting method was used to observe the growth of cells after 48 hours, and chemiluminescence method was utilized to measure the level of progesterone in culture supernatant. Results: The cell proliferation was enhanced in the FSH group, while the proliferation was inhibited in the endometriosis group and the endometriosis plus BMP-15 group, compared to the control group, both of which, were statistically significant. Compared to the control group, the progesterone levels from the culture supernatant of granular cells were significantly elevated in the FSH group, tubal group and endometriosis group. The secretion of progesterone in the endometriosis group was lower than that in the tubal group. After addition of FSH into the endometriosis group (the endometriosis plus FSH group), the secretion level of progesterone was significantly increased, compared to the control group and the endometriosis group. After adding BMP-15 into the endometriosis group (the endometriosis plus BMP-15 group), the secretion level of progesterone was increased, compared to the control group. Conclusions: FSH, but not BMP-15, was able to enhance the proliferation and progesterone secretion of granular cells. The proliferation of granular cells and secretion of progesterone were inhibited by the follicular fluid from patients with endometriosis, which was reversed by FSH. However, BMP-15 had no effect on the outcome of follicular fluid from patients with endometriosis.

[The combined effects of family history of cardiovascular disease and overweight on ischemic stroke incidence among the Mongolian population].

Objective: To investigate the cumulative effect of family history of cardiovascular disease(CVD)and overweight on ischemic stroke events in the Mongolian population. Methods: Study participants were recruited from 32 villages from May 2002 to August 2012 in Kezuohou Banner(county)and Naiman Banner in Inner Mongolia, China. Among 3 457 Mongolian people aged ≥20 years old living in these villages, 2 589 were selected to participate in this study. None of the participants had chronic kidney disease, malignant tumor, thyroid disease or adrenalopathy, or acute infectious disease. The 2 589 participants were followed for a mean of 9.2 years. Six participants were lost to follow up, resulting in a follow-up rate of 99.8%. Information collected included demographic characteristics, lifestyle risk factors, alcohol consumption, cigarette smoking, history of disease, family history of CVD, and physical examination. Ischemic stroke incidence information was collected during follow-up. All participants were categorized into four subgroups according to family history of CVD and overweight status. Cox proportional hazards models were used to estimate the hazard ratios(HR)and 95% CI of ischemic stroke events among subgroups, compared with the subgroup with no family history of CVD and body mass index(BMI)<24 kg/m2(the reference group). Results: Among 2 589 participants, 76 ischemic stroke events occurred after follow-up, and 8 were excluded because of lack of key data. Finally, 2 581 participants were included in the analysis, and the incidence density was 323/100 000 person-years. The cumulative incidence rates of ischemic stroke were 2.48%, 1.86%, 6.67% and 9.00% in the no family history of CVD and BMI <24 kg/m2, no family history of CVD and BMI ≥24 kg/m2, family history of CVD and BMI <24 kg/m2 and family history of CVD and BMI ≥ 24 kg/m2 subgroups, respectively. Using the Cox proportional hazards model, after further adjustment for age, gender, smoking, drinking, FPG, hypertension, total cholesterol, triglycerides, and heart rate, the risk of ischemic stroke in the subgroup with a family history of CVD and BMI ≥24 kg/m2 was higher than the reference group(HR: 2.61, 95% CI: 1.16-5.87). However, the risk of ischemic stroke in other two groups was not statistically significant compared with the reference group. The HR(95% CI)values in the no family history of CVD and BMI ≥24 kg/m2and family history of CVD and BMI <24 kg/m2 subgroups were 1.18(0.5- 2.39)and 1.27(0.67- 2.42), respectively. Conclusion: In the Mongolian population, a family history of CVD and coexistent overweight may increase the risk of ischemic stroke events, suggesting that in people with family history of cardiovascular disease, weight control is conducive to the prevention of ischemic stroke.

Construction of an infectious plasmid clone of Muscovy duck parvovirus by TA cloning and creation of a partially attenuated strain.

Muscovy duck parvovirus (MDPV) infection is a highly contagious and fatal disease of Muscovy ducklings. The infectious clone methodology is a valuable tool to study the pathogenic mechanisms of viruses, but no infectious clone of MDPV is yet available. In this study, a plasmid clone containing the full-length genome of MDPV was constructed using the TA cloning methodology. This MDPV clone was found to be infectious after transfection of primary Muscovy duck embryo fibroblast cells and passage in embryonated Muscovy duck eggs. Site-directed mutagenesis showed that the K75N mutation in the VP1 protein of MDPV resulted in the partial attenuation of the virus. The availability of an MDPV infectious clone can facilitate investigation of the pathogenic mechanisms of MDPV and development of vaccines against diseases caused by MDPV.

[Multicenter evaluation of the diagnostic efficacy of jaundice color card for neonatal hyperbilirubinemia].

Objective: To evaluate the diagnostic efficacy and practicality of the Jaundice color card (JCard) as a screening tool for neonatal jaundice. Methods: Following the standards for reporting of diagnostic accuracy studies (STARD) statement, a multicenter prospective study was conducted in 9 hospitals in China from October 2019 to September 2021. A total of 845 newborns who were admitted to the hospital or outpatient department for liver function testing due to their own diseases. The inclusion criteria were a gestational age of ≥35 weeks, a birth weight of ≥2 000 g, and an age of ≤28 days. The neonate's parents used the JCard to measure jaundice at the neonate's cheek. Within 2 hours of the JCard measurement, transcutaneous bilirubin (TcB) was measured with a JH20-1B device and total serum bilirubin (TSB) was detected. The Pearson's correlation analysis, Bland-Altman plots and the receiver operating characteristic (ROC) curve were used for statistic analysis. Results: Out of the 854 newborns, 445 were male and 409 were female; 46 were born at 35-36 weeks of gestational age and 808 were born at ≥37 weeks of gestational age. Additionally, 432 cases were aged 0-3 days, 236 cases were aged 4-7 days, and 186 cases were aged 8-28 days. The TSB level was (227.4±89.6) µmol/L, with a range of 23.7-717.0 µmol/L. The JCard level was (221.4±77.0) µmol/L and the TcB level was (252.5±76.0) µmol/L. Both the JCard and TcB values showed good correlation (r=0.77 and 0.80, respectively) and agreements (96.0% (820/854) and 95.2% (813/854) of samples fell within the 95% limits of agreement, respectively) with TSB. The JCard value of 12 had a sensitivity of 0.93 and specificity of 0.75 for identifying a TSB ≥205.2 µmol/L, and a sensitivity of 1.00 and specificity of 0.35 for identifying a TSB ≥342.0 µmol/L. The TcB value of 205.2 µmol/L had a sensitivity of 0.97 and specificity of 0.60 for identifying TSB levels of 205.2 µmol/L, and a sensitivity of 1.00 and specificity of 0.26 for identifying TSB levels of 342.0 µmol/L. The areas under the ROC curve (AUC) of JCard for identifying TSB levels of 153.9, 205.2, 256.5, and 342.0 µmol/L were 0.96, 0.92, 0.83, and 0.83, respectively. The AUC of TcB were 0.94, 0.91, 0.86, and 0.87, respectively. There were both no significant differences between the AUC of JCard and TcB in identifying TSB levels of 153.9 and 205.2 µmol/L (both P>0.05). However, the AUC of JCard were both lower than those of TcB in identifying TSB levels of 256.5 and 342.0 µmol/L (both P<0.05). Conclusions: JCard can be used to classify different levels of bilirubin, but its diagnostic efficacy decreases with increasing bilirubin levels. When TSB level are ≤205.2 µmol/L, its diagnostic efficacy is equivalent to that of the JH20-1B. To prevent the misdiagnosis of severe jaundice, it is recommended that parents use a low JCard score, such as 12, to identify severe hyperbilirubinemia (TSB ≥342.0 µmol/L).

Water equivalent path length measurement in proton radiotherapy using time resolved diode dosimetry.

PURPOSE: To verify water equivalent path length (WEPL) before treatment in proton radiotherapy using time resolved in vivo diode dosimetry. METHODS: Using a passively scattered range modulated proton beam, the output of a diode driving a fast current-to-voltage amplifier is recorded at a number of depths in a water tank. At each depth, a burst of overlapping single proton pulses is observed. The rms duration of the burst is computed and the resulting data set is fitted with a cubic polynomial. RESULTS: When the diode is subsequently set to an arbitrary depth and the polynomial is used as a calibration curve, the "unknown" depth is determined within 0.3 mm rms. CONCLUSIONS: A diode or a diode array, placed (for instance) in the rectum in conjunction with a rectal balloon, can potentially determine the WEPL at that point, just prior to treatment, with submillimeter accuracy, allowing the beam energy to be adjusted. The associated unwanted dose is about 0.2% of a typical single fraction treatment dose.

[A model analysis on the knowledge-attitude-practice of children guardians in Jiangxi, Shanghai and Qinghai].

Objective: To understand the knowledge attitude and practice (KAP) on vaccination among children's parents in Jiangxi, Shanghai, and Qinghai and explore the factors influencing KAP. Methods: The study selected two counties/districts in Jiangxi, Shanghai, and Qinghai, respectively, by stratified sampling and used a unified questionnaire to investigate the parental KAP of vaccination. A structural equation model (SEM) was used to explore factors influencing parental KAP, as well as the relationship between knowledge and behavior. Results: Of the 760 valid questionnaires, the knowledge of vaccination among children's parents was better, and the vaccination knowledge of parents in Qinghai and Shanghai were slightly better than those in Jiangxi. Parents mainly obtained vaccination knowledge through medical staff and vaccination manuals. The fitting degree of SEM was relatively good; the root mean square error of approximation of the model is 0.033. The higher the parents' education level, the better their knowledge of vaccination (ß̂=0.082). Parental vaccination knowledge could influence whether the vaccinated children stay for half an hour in the clinics (ß̂=0.541). It could also impact whether parents giving up vaccinating their children in the face of media reports about the adverse effects of vaccinations (ß̂=0.515). Conclusions: The knowledge of vaccination among the parents in Jiangxi, Shanghai, and Qinghai was quite good. Moreover, we should pay more attention to the mass media programs and vaccination knowledge among parents with low or middle education backgrounds. Vaccination knowledge can be disseminated through medical staff, vaccination manuals, or mobile applications.

Direct absorbed dose to water determination based on water calorimetry in scanning proton beam delivery.

PURPOSE: The aim of this manuscript is to describe the direct measurement of absolute absorbed dose to water in a scanned proton radiotherapy beam using a water calorimeter primary standard. METHODS: The McGill water calorimeter, which has been validated in photon and electron beams as well as in HDR 192Ir brachytherapy, was used to measure the absorbed dose to water in double scattering and scanning proton irradiations. The measurements were made at the Massachusetts General Hospital proton radiotherapy facility. The correction factors in water calorimetry were numerically calculated and various parameters affecting their magnitude and uncertainty were studied. The absorbed dose to water was compared to that obtained using an Exradin T1 Chamber based on the IAEA TRS-398 protocol. RESULTS: The overall 1-sigma uncertainty on absorbed dose to water amounts to 0.4% and 0.6% in scattered and scanned proton water calorimetry, respectively. This compares to an overall uncertainty of 1.9% for currently accepted IAEA TRS-398 reference absorbed dose measurement protocol. The absorbed dose from water calorimetry agrees with the results from TRS-398 well to within 1-sigma uncertainty. CONCLUSIONS: This work demonstrates that a primary absorbed dose standard based on water calorimetry is feasible in scattered and scanned proton beams.

Commissioning a passive-scattering proton therapy nozzle for accurate SOBP delivery.

Proton radiotherapy centers that currently use passively scattered proton beams do field specific calibrations for a non-negligible fraction of treatment fields, which is time and resource consuming. Our improved understanding of the passive scattering mode of the IBA universal nozzle, especially of the current modulation function, allowed us to re-commission our treatment control system for accurate delivery of SOBPs of any range and modulation, and to predict the output for each of these fields. We moved away from individual field calibrations to a state where continued quality assurance of SOBP field delivery is ensured by limited system-wide measurements that only require one hour per week. This manuscript reports on a protocol for generation of desired SOBPs and prediction of dose output.

Reply to comment on 'Modelling of surface energies of elemental crystals'.

In reply to the comment by Luo et al, our theoretical model for the surface energy of elemental crystals is further developed to improve the prediction accuracy of the surface energy of the high-Miller-index facets. It is considered that the previous predicted unit surface area could not denote the actual one since the facets now are uneven. With the modification, the accuracy for the prediction of surface energy in units of J m(-2) is improved.

Size-dependent thermodynamic properties of metallic nanowires.

Analytical models for size-dependent melting temperature Tm(D), melting enthalpy DeltaHm(D), and surface energy gammasv(D) of metallic nanowires have been proposed in terms of the unified nanothermodynamical model where D denotes the diameter of nanowire. As D decreases, Tm(D), DeltaHm(D), and gammasv(D) functions are found to decrease almost with the same size-dependent trend. Due to the inclusion of the effect of dimensionality, the developed model can be applied to other low-dimensional systems. It is found that the ratio of depression of these thermodynamic parameters for spherical nanoparticle, nanowire, and thin film is 3:2:1 when D is large enough (>20h with h being the atomic diameter). The validity of the model is verified by the data of experiments, molecular dynamics simulations, and other theoretical models.

Metabolic profiling putatively identifies plasma biomarkers of male infertility using UPLC-ESI-IT-TOFMS.

Male infertility has become a global health problem. Currently, the diagnosis of male infertility depends on the results of semen quality or requires invasive surgical intervention. The process is complex and time-consuming. Metabolomics is an emerging platform with unique advantages in disease diagnosis and pathological mechanism research. In this study, ultra-performance liquid chromatography-electrospray ionization-ion trap-time of flight mass spectrometry (UPLC-ESI-IT-TOFMS) combined with chemometrics methods was used to discover potential biomarkers of male infertility based on non-targeted plasma metabolomics. Plasma samples from healthy controls (HC, n = 43) and various types of infertile patients, i.e., patients having oligozoospermia (OS, n = 36), asthenospermia (AS, n = 56) and erectile dysfunction (ED, n = 45) were analyzed by UPLC-ESI-IT-TOFMS. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were performed. The results of OPLS-DA showed that HCs could be discriminated from infertile patients including OS (R 2 = 0.903, Q 2 = 0.617, AUC = 0.992), AS (R 2 = 0.985, Q 2 = 0.658, AUC = 0.999) or ED (R 2 = 0.942, Q 2 = 0.500, AUC = 0.998). Some potential biomarkers were successfully discovered by variable selection methods and variable important in the projection (VIP) in combination with the T-test. Statistical significance was set at p < 0.05; the Benjamini-Hochberg false discovery rate was used to reduce type 1 errors resulting from multiple comparisons. The identified biomarkers were associated with energy consumption, hormone regulation and antioxidant defenses in spermatogenesis. To elucidate the pathophysiology of male infertility, relative metabolic pathways were studied. It was found that male infertility is closely related to disturbed phospholipid metabolism, amino acid metabolism, steroid hormone biosynthesis metabolism, metabolism of fatty acids and products of carnitine acylation, and purine and pyrimidine metabolisms. Plasma metabolomics provides a novel strategy for the diagnosis of male infertility and offers a new insight to study pathogenesis mechanism.

Anti-CD25 mAb, anti-IL2 mAb, and IL2 block tolerance induction through anti-CD154 mAb and rapamycin in xenogeneic islet transplantation.

BACKGROUND: We have used anti-CD154 monoclonal antibody (mAb; MR1) and rapamycin (rapa) to induce tolerance to islet xenografts. The aim of this study was to investigate whether classical anergy and/or regulation by interleukin (IL)2-dependent CD25+ T regulatory cells played roles in the induction and maintenance of tolerance in this model. METHODS: Streptozotocin-induced diabetic mice were transplanted with rat islets. We performed the following groups: control group, islet transplantation without therapy; rapamycin group, 0.2 mg/kg by oral gavage on days 0, 1, 2, and every other day to day 14; anti-CD154 mAb (MR1) group, 0.5 mg intraperitoneally on days 0, 2, and 4; combination therapy group with rapa and MR1. We then administered in addition to the combination therapy with early (from days 0 to 14 [for IL2] or to 28 [for anti-IL2 mAb and anti-CD25 mAb] post-transplantation) or late (from days 100 to 114 [for IL2] or to 128 [for anti-IL2 mAb and anti-CD25 mAb] posttransplantation) recombinant IL2 (2000 U, intraperitoneally twice a day), a neutralizing anti-IL2 mAb (S4B6-1, 0.3 mg intraperitoneally twice weekly), and a depleting anti-CD25 mAb (PC61, 0.3 mg intraperitoneally twice weekly), respectively. Histology was performed at time of rejection. RESULTS: Rapa and MR1 therapy alone significantly prolonged xenograft survival compared to the control group: median graft survival was 34 days versus 17 days (P<.05) and 98 days versus 17 days (P<.05), respectively, but rejection still occurred. Combination therapy with MR1 and rapa allowed indefinite graft survival (median graft survival [MGS]>200 days, P<.001). When exogenous IL2 was administered early with MR1 and rapa, rapid rejection developed in 18 of 18 mice (MGS 7 days), whereas when IL2 was given late, only 3 of 10 developed rejection. Early administration of anti-IL2 mAb led to rejection in 10 of 10 mice (MGS 42 days), whereas late administration led to rejection in only one of four mice. Early administration of anti-CD25 mAb led to rejection in eight of nine mice (MGS 49 days), whereas late administration led to rejection in only three of seven mice. CONCLUSIONS: Rapa and MR1 allowed indefinite graft survival of islet xenografts. Classical anergy and regulation by IL2-dependent CD25+ T regulatory cells were critical in the induction of tolerance in the immediate posttransplantation period and less important for maintenance of tolerance.

Proton therapy of prostate cancer by anterior-oblique beams: implications of setup and anatomy variations.

Proton therapy of prostate by anterior beams could offer an attractive option for treating patients with hip prosthesis and limiting the high-dose exposure to the rectum. We investigated the impact of setup and anatomy variations on the anterior-oblique (AO) proton plan dose, and strategies to manage these effects via range verification and adaptive delivery. Ten patients treated by bilateral (BL) passive-scattering proton therapy (79.2 Gy in 44 fractions) who underwent weekly verification CT scans were selected. Plans with AO beams were additionally created. To isolate the effect of daily variations, initial AO plans did not include range uncertainty margins. The use of fixed planning margins and adaptive range adjustments to manage these effects was investigated. For each case, the planned dose was recalculated on weekly CTs, and accumulated on the simulation CT using deformable registration to approximate the delivered dose. Planned and accumulated doses were compared for each scenario to quantify dose deviations induced by variations. The possibility of estimating the necessary range adjustments before each treatment was explored by simulating the procedure of a diode-based in vivo range verification technique, which would potentially be used clinically. The average planned rectum, penile bulb and femoral heads mean doses were smaller for initial AO compared to BL plans (by 8.3, 16.1 and 25.9 Gy, respectively). After considering interfractional variations in AO plans, the target coverage was substantially reduced. The maximum reduction of V 79.2/D 95/D mean/EUD for AO (without distal margins) (25.3%/10.7/1.6/4.9 Gy, respectively) was considerably larger than BL plans. The loss of coverage was mainly related to changes in water equivalent path length of the prostate after fiducial-based setup, caused by discrepancies in patient anterior surface and bony-anatomy alignment. Target coverage was recovered partially when using fixed planning margins, and fully when applying adaptive range adjustments. The accumulated organs-at-risk dose for AO beams after range adjustment demonstrated full sparing of femoral heads and superior sparing of penile bulb and rectum compared to the conventional BL cases. Our study indicates that using AO beams makes prostate treatment more susceptible to target underdose induced by interfractional variations. Adaptive range verification/adjustment may facilitate the use of anterior beam approaches, and ensure adequate target coverage in every fraction of the treatment.

Investigation of time-resolved proton radiography using x-ray flat-panel imaging system.

Proton beam therapy benefits from the Bragg peak and delivers highly conformal dose distributions. However, the location of the end-of-range is subject to uncertainties related to the accuracy of the relative proton stopping power estimates and thereby the water-equivalent path length (WEPL) along the beam. To remedy the range uncertainty, an in vivo measurement of the WEPL through the patient, i.e. a proton-range radiograph, is highly desirable. Towards that goal, we have explored a novel method of proton radiography based on the time-resolved dose measured by a flat panel imager (FPI). A 226 MeV pencil beam and a custom-designed range modulator wheel (MW) were used to create a time-varying broad beam. The proton imaging technique used exploits this time dependency by looking at the dose rate at the imager as a function of time. This dose rate function (DRF) has a unique time-varying dose pattern at each depth of penetration. A relatively slow rotation of the MW (0.2 revolutions per second) and a fast image acquisition (30 frames per second, ~33 ms sampling) provided a sufficient temporal resolution for each DRF. Along with the high output of the CsI:Tl scintillator, imaging with pixel binning (2 × 2) generated high signal-to-noise data at a very low radiation dose (~0.1 cGy). Proton radiographs of a head phantom and a Gammex CT calibration phantom were taken with various configurations. The results of the phantom measurements show that the FPI can generate low noise and high spatial resolution proton radiographs. The WEPL values of the CT tissue surrogate inserts show that the measured relative stopping powers are accurate to ~2%. The panel did not show any noticeable radiation damage after the accumulative dose of approximately 3831 cGy. In summary, we have successfully demonstrated a highly practical method of generating proton radiography using an x-ray flat panel imager.

Fine-tuning the synthesis of ZnO nanostructures by an alcohol thermal process.

A simple and efficient alcohol thermal technique was applied to control the growth of the dimensions and morphology of ZnO nanostructures under mild conditions, where surfactant was not necessary. The size of ZnO nanocrystals increased with growth temperature and they transformed into nanorods with different aspect ratios through tuning the reaction time. The length of nanorods increased significantly with the reaction time, but their thickness only slightly increased. The as-prepared ZnO nanocrystals were monocrystalline and the growth orientation of ZnO nanorods was [001]. Photoluminescence measurements showed a blue shift in violet emission with a reduction in crystal size and revealed the quantum confinement effect. Electron irradiation induced structural damage was observed in the ZnO nanorods synthesized at 120 degrees C. Experimental results proved that the possible growth mechanism of ZnO nanostructures was oriented attachment.

Identification and quality assessment of Houttuynia cordata injection using GC-MS fingerprint: a standardization approach.

Houttuynia cordata (Saururaceae) injection (HCI) was widely used to treat disease in China. At present, there were about 40 factories producing HCI, but a good quality standard for its quality control was lacking. In this study, an optimized and validated gas chromatography-mass spectrum (GC-MS) method was applied for the fingerprint analysis of 340 batches of HCI from 34 Chinese pharmaceutical factories. The results showed that HCI from the same factory had very similar GC-MS fingerprints, and evident difference existed among different factories. The representative fingerprints from 20 factories whose intra-factory correlation coefficients were over 0.90 and inter-factory correlation coefficients were over 0.75 were used to calculate the mean fingerprint of all samples. Spectral correlative chromatogram (SCC) was adopted to identify common component in different samples. Fifteen main "common components" were obtained. The mean fingerprint containing those 15 components was suggested to be used as characteristic fingerprint for the rapid identification of HCI and evaluation of the consistency of HCI from factory to factory and from batch to batch.