COMPACT GANTRY WITH LARGE ENERGY ACCEPTANCE*

Abstract Existing proton beam therapy gantries weight 100+ tons and require large (three stories) heavily shielded rooms to house them. Pioneering work by Trbojevic et al [1] using fixed field alternating gradient (FFAG) gantry concept demonstrated the potential of both reducing the size of the gantry as well as increasing the energy acceptance. In this paper we present a new variation of a compact superconducting FFAG gantry. The gantry consists of three, small aperture, 7-bend achromat sections followed by transverse scanning magnets. The 7-bend achromat contains high field superconducting combined-function bending magnets. This gantry provides a large (+/-20%) energy acceptance for fast depth scanning. We present the analysis of the beam tracking and show that it is possible to scan the ion beam over a large volume of roughly 1 cubic liter, with minimal distortion in the beam shape without changing the fields of the superconducting magnets

Upregulation of stromal cell-derived factor 1 (SDF-1) is associated with macrophage infiltration in renal ischemia-reperfusion injury.

Stromal cell-derived factor-1(SDF-1) is a chemotactic and angiogenic factor that mediates the repair of various tissues. As macrophages are important contributors to ischemic kidney injury, we examine the role of SDF-1 in a rodent model of ischemia-reperfusion (I/R) injury.Male wild-type (WT) (C57BL/6) mice were subjected to bilateral I/R injury or sham operation in the presence or absence of macrophage depletion (liposomal clodronate [0.2 ml/20-25 g body weight i.p.]). Macrophage accumulation was assessed by immunohistochemistry. Tissue levels of SDF-1 (ELISA) and SDF-1 mRNA expression (real-time PCR) were measured. The cellular location of SDF-1 was assessed using immunohistochemical staining.Immunofluorescence staining of renal tissue sections confirmed macrophage depletion by liposomal clodronate. SDF-1 production was elevated in response to I/R injury and was significantly increased upon macrophage depletion. SDF-1 positive cells initially appeared initially in the cortex, and subsequently diffused to the outer medulla after I/R injury.Our study demonstrates that SDF-1 is significantly upregulated during renal I/R. We hypothesize that SDF-1 upregulation may be an important macrophage effector mechanism during I/R injury

Correlation of Indoleamine-2,3-Dioxygenase and Chronic Kidney Disease: A Pilot Study

Objective. To explore the correlation of indoleamine-2,3-dioxygenase (IDO) and chronic kidney disease (CKD). Methods. A total of 154 CKD patients and 42 non-CKD patients were recruited. Patients were grouped into ACR1~ACR3 (300 mg/g). Biomarkers in different groups were compared by ANOVA. Correlation was calculated by Pearson or Spearman analysis and binary logistic regression. The ROC curve was also performed. Results. The levels of albumin, serum creatinine (sCr), and IDO in non-CKD patients were significantly different from those in CKD3-CKD5 stages (p<0.05). IDO was correlated with age, proteinuria, ACR, and eGFR (p<0.01). After adjusting for CKD-related indices, ln(IDO) was an independent risk factor for CKD (3.48, p<0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.0466 and yielded a sensitivity of 83.8% and a specificity of 75%. Hemoglobin, total protein, and albumin in the ACR1 group were significantly higher than those in the ACR2 and ACR3 groups (p<0.01), while sCr and IDO levels were significantly lower than those in the ACR2 and ACR3 groups (p<0.01 or p<0.05). After adjusting for CKD-related indices, ln(IDO) was still an independent risk factor for ACR (OR=2.7, p<0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.075 and yielded a sensitivity of 71.9% and a specificity of 72.2%. Conclusion. IDO may be a promising biomarker to predict CKD and assess kidney function

Effect of continued nitrogen enrichment on greenhouse gas emissions from a wetland ecosystem in the Sanjiang Plain, Northeast China: A 5 year nitrogen addition experiment

Mounting evidence supports that wetland ecosystems, one of the largest carbon pools on the earth, are exposed to ample nitrogen (N) additions due to atmospheric deposition or N loading from upstream agricultural fertilizer application. However, our understanding of how N enrichment affects the fluxes of greenhouse gases (GHGs) in wetlands is weak. A 5year N addition experiment was conducted to examine the responses of CH4 and N2O fluxes as well as ecosystem respiration from wetlands in the Sanjiang Plain, Northeast China, through 2005 to 2009. Four levels of N addition (control, 0kgN ha(-1)yr(-1); low-level, 60kgN ha(-1)yr(-1); medium-level, 120kgN ha(-1)yr(-1); high-level, 240kgN ha(-1)yr(-1)) were designed in this study. Overall, our results show that medium and high levels of N addition increased ecosystem respiration by 28% and 69% (P0.05). High-level N fertilization exerted stronger effects on ecosystem respiration in the initial year than the following years. It indicated that the effects of high-level N fertilization on CO2 might be overestimated by short-term observations. High-level N fertilization increased N2O emissions by 396% over the 5years (P0.05). N2O emission under high-level N addition in the first and fifth years showed stronger pronounced responses to N addition compared with that from the third and fourth years, indicating the importance of long-term field observation. Over the 5years, however, the low and medium-level N addition showed no effect on N2O emissions. The four levels of N addition exerted no effect on CH4 emissions (P>0.05). Furthermore, the relationship between GHGs and soil temperature or water table depth varied among different plots and experimental time. Our findings highlighted the importance of gas species, experimental time, and the amount of fertilizer N with regard to the responses of GHG emissions to N fertilization

Localized Fe(II)-Induced Cytotoxic Reactive Oxygen Species Generating Nanosystem for Enhanced Anticancer Therapy

The anticancer therapy on the basis of reactive oxygen species (ROS)-mediated cellular apoptosis has achieved great progress. However, this kind of theraputic strategy still faces some challenges such as light, photosensitizer and oxygen (O₂) dependence. In this article, a ROS-mediated anticancer therapy independent of light, photosensitizer and oxygen was established based on a Fe²⁺-induced ROS-generating nanosystem. First, artemisinin (ART) was loaded in porous magnetic supraparticles (MSP) by a nanodeposition method. Then, the poly­(aspartic acid)-based polymer, which consisted of dopamine, indocyanine green, and polyethylene glycol side chain, was coated onto the surface of ART-loaded MSP. When the nanoparticles entered into cancer cells, a reaction of Fe²⁺-mediated cleavage of the endoperoxide bridge contained in ART occurred and subsequent a large amount of ROS was generated. Moreover, a NIR light was used to effectively increase the local temperature of tumor in virtue of the superior photothermal effects of MSP, which enabled us to accelerate the ROS generation and achieved an enhanced ROS yield. The newly developed nanodrug system displayed a high level of intracellular ROS generation, leading to the desired killing efficacy against malignant cells and solid tumor. This smart nanosystem holds great potential to overcome the existing barrier in PDT and opens a promising avenue for anticancer therapy