Diagnosing ratio of electron density to collision frequency of plasma surrounding scaled model in a shock tube using low-frequency alternating magnetic field phase shift

A non-contact low-frequency(LF)method of diagnosing the plasma surrounding a scaled model in a shock tube is proposed.This method utilizes the phase shift occurring after the transmission of an LF alternating magnetic field through the plasma to directly measure the ratio of the plasma loop average electron density to collision frequency.An equivalent circuit model is used to analyze the relationship of the phase shift of the magnetic field component of LF electromagnetic waves with the plasma electron density and collision frequency.The applicable range of the LF method on a given plasma scale is analyzed.The upper diagnostic limit for the ratio of the electron density(unit:m^(-3))to collision frequency(unit:Hz)exceeds 1×10^(11),enabling an electron density to exceed 1×10^(20)m^(-3)and a collision frequency to be less than 1 GHz.In this work,the feasibility of using the LF phase shift to implement the plasma diagnosis is also assessed.Diagnosis experiments on shock tube equipment are conducted by using both the electrostatic probe method and LF method.By comparing the diagnostic results of the two methods,the inversion results are relatively consistent with each other,thereby preliminarily verifying the feasibility of the LF method.The ratio of the electron density to the collision frequency has a relatively uniform distribution during the plasma stabilization.The LF diagnostic path is a loop around the model,which is suitable for diagnosing the plasma that surrounds the model.Finally,the causes of diagnostic discrepancy between the two methods are analyzed.The proposed method provides a new avenue for diagnosing high-density enveloping plasma.

Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations:a functional magnetic resonance imaging study

AIM:To study functional brain abnormalities in patients with hypertensive retinopathy(HR)and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations(fALFFs)method.METHODS:Twenty HR patients and 20 healthy controls(HCs)were respectively recruited.The age,gender,and educational background characteristics of the two groups were similar.After functional magnetic resonance imaging(fMRI)scanning,the subjects’spontaneous brain activity was evaluated with the fALFF method.Receiver operating characteristic(ROC)curve analysis was used to classify the data.Further,we used Pearson’s correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR.RESULTS:The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus(RO-MFG)and right lingual gyrus.In contrast,the values of fALFFs in the left middle temporal gyrus(MTG),left superior temporal pole(STP),left middle frontal gyrus(MFG),left superior marginal gyrus(SMG),left superior parietal lobule(SPL),and right supplementary motor area(SMA)were higher in the HR group.The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group(P<0.001).The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores(r=0.9232;P<0.0001)and depression scores(r=0.9682;P<0.0001).CONCLUSION:fALFF values in multiple brain regions of HR patients are abnormal,suggesting that these brain regions in HR patients may be dysfunctional,which may help to reveal the pathophysiological mechanisms of HR.

Clinical efficacy of magnetic vibration magnetoelectric therapy in the treatment of chronic prostatitischronic pelvic pain syndrome

BACKGROUND The prominent symptoms of chronic pelvic pain syndrome(CPPS)are urogenital pain,lower urinary tract symptoms,psychological problems,and sexual dysfunction.Traditional pharmacological treatments have poor efficacy and more untoward reaction and complications.Magnetic vibration magnetoelectric therapy is a non-invasive form of physiotherapy.Nevertheless,its effectiveness in improving urinary discomfort and relieving pain in patients requires further exploration.AIM To investigate the clinical efficacy of the magnetic vibration magnetoelectric therapy instrument in the treatment of chronic prostatitis(CP)/CPPS.METHODS Seventy patients with CP/CPPS were collected from the outpatient clinic and ward of the Department of Male Medicine,Jiangsu Province Hospital of Traditional Chinese Medicine,and were treated with magnetic vibration magnetoelectric therapy once a day for a period of 14 d.National Institutes of healthchronic prostatitis symptom index(NIH-CPSI),international index of erectile function 5(IIEF-5),premature ejaculation diagnostic tool(PEDT),generalized anxiety disorder(GAD),patient health questionnaire,the pain catastrophizing scale(PCS)and traditional Chinese medicine syndrome(TCMS)scores were performed before and after treatment.RESULTS The total effective rate of treatment was 58.5%,and the total NIH-CPSI score,pain symptoms,voiding symptoms,quality of life,IIEF-5,PEDT,GAD,PCS and TCMS scores all decreased significantly(P<0.05).CONCLUSION Magnetic vibration magnetotherapy is effective in improving urinary discomfort,relieving pain,improving quality of life,improving sexual dysfunction and relieving negative emotions such as anxiety in patients with CP/CPPS.

Effect of Acupuncture Cooperated with Low-frequency Repetitive Transcranial Magnetic Stimulation on Chronic Insomnia： A Randomized Clinical Trial

The effect of acupuncture cooperated with low-frequency repetitive transcranial magnetic stimulation （rTMS） on chronic insomnia was explored. Seventy-eight patients with chronic insomnia were randomly allocated into two groups： treatment group and control group. In the treatment group, the patients received acupuncture combined with rTMS treatment, and those in the control group were given acupuncture cooperated with sham rTMS treatment, 3 days per week for 4 weeks. Before and after treatment, the primary outcomes including the scores on Insomnia Severity Index （ISI） and Pittsburgh Sleep Quality Index （PSQI） and the secondary outcomes including total sleep time （TST）, sleep onset latency （SOL）, wake after sleep onset （WASO）, sleep efficiency （SE%） recorded by sleeping diary and actigraphy were observed in both groups. Seventy-five participants finished the study （38 in treatment group and 37 in control group respectively）. After treatment, the scores in the two groups were improved significantly, more significantly in the treatment group than in the control group. It can be inferred that acupuncture cooperated with rTMS can effectively improve sleep quality, enhance the quality of life of patients and has less side effects.

Analysis of the Effect of Limb Rehabilitation Therapy Combined with Transcranial Magnetic Stimulation Therapy on Muscle Activity in Patients with Upper Limb Dysfunction After Cerebral Infarction

Objective:To analyze the effect of limb rehabilitation therapy combined with transcranial magnetic stimulation therapy on muscle activity in patients with upper limb dysfunction after cerebral infarction(CI).Methods:320 patients with upper limb dysfunction after CI were selected,all of whom were treated in our hospital between June 2021 and June 2023.They were randomly grouped according to the lottery method into the control group(limb rehabilitation therapy,160 cases)and the intervention group(transcranial magnetic stimulation therapy+limb rehabilitation therapy,160 cases).The upper limb function scores,neuro-electrophysiological indicators,daily living ability scores,and quality of life scores of the two groups were compared.Results:Compared with the control group,upper limb function scores and daily living ability scores in the intervention group were higher after treatment,and the neuro-electrophysiological indicators of the intervention group were lower after treatment(P<0.05).Conclusion:Transcranial magnetic stimulation therapy combined with limb rehabilitation therapy has significant effects in patients with upper limb dysfunction after CI and is worthy of promotion and application.

Experiment on low-frequency electromagnetic waves propagating in shock-tube-generated magnetized cylindrical enveloping plasma

We propose a method of applying a static magnetic field to reduce the attenuation of the magnetic field component(SH) of low-frequency electromagnetic(LF EM) waves in dense plasma. The principle of this method is to apply a static magnetic field to limit electron movement, thereby increasing the equivalent resistance and thus reducing the induced current and SH. We consider the static magnetic field acting on the plasma of the entire induced current loop rather than on the local plasma, where the induced current is excited by the magnetic field component of LF EM waves. Analytical expressions of SH suitable for magnetized cylindrical enveloping plasma are derived by adopting an equivalent circuit approach, by which SHis calculated with respect to various plasma parameter settings. The results show that SH can be reduced under a static magnetic field and the maximum magnetic field strength that mitigates blackout is less than 0.1 T. Experiments in which LF EM waves propagate in a shock-tubegenerated magnetized cylindrical enveloping plasma are also conducted. SH measured under the magnetic field(the magnetic field strength B0 acting on the magnetic field probe was about0.06 T) reduces at f=10 MHz and f=30 MHz when ne≈1.9×1013 cm-3, which is consistent with theoretical results. The verification of the theory thus suggests that applying a static magnetic field with a weak magnetic field has the potential to improve the transmission capacity of LF EM waves in dense plasma.

General Properties of Low-frequency Power Losses in Fe-based Nanocrystalline Soft Magnetic Alloys

The dependences of the power loss per cycle on frequency f and amplitude flux density Bm have been investigated for the three main original magnetic states in five sorts of Fe-based nanocrystalline soft magnetic alloys in the ranges of 10 Hz<=f<=1000 Hz and 0.4 T<= Bm <=1.0 T. The total loss P is decomposed into the sum of the hysteresis loss Physt, the classical eddy current loss Pel and the excess loss Pexc. Physt has been found to be proportional to Bm^2 and f. The behavior of Pexc/f vs f being equivalent to P/f vs f clearly exhibits nonlinearity in the range not more than about 120 Hz, whereas the behavior of P/f vs f roughly shows linearity in the range far above 100 Hz and not more than 1000 Hz. In the range up to 1000 Hz, Physt is dominant in the original high permeability state and the state of low residual flux density, whereas Pexc in the state of high residual flux density is dominant in the wider range above about 100 Hz. The framework of the statistical theory of power loss has been used for representing the behavior of Pexc/f vs f. It has been found that the number n of the simultaneously active 'Magnetic Objects' linearly varies as n = n0 + Hexc/H0 as a function of the dynamic field Hexc in the range below about 120 Hz, whereas n approximately follows a law of the form n = n0 + (Hexc/H0)^m with 1 < m < 2 in the range far above 100 Hz and not more than 1000 Hz. The values of the field HO in principle related to the microstructure and the domain structure have been calculated for the three states.

THE INFLUENCE OF LOW-FREQUENCY VARYING MAGNETIC FIELDON THE PULSATILE FLOW IN A RIGID ROUND TUBE

In this paper, the analytic solution of the dynamical equation of the pulsatile flow in a rigid round tube under the low-frequency varying magnetic field is obtained. The velocity distribution and the flow impedance are calculated. The results of e valuable for understanding the influence of low-frequency varying magnetic field on hemodynamics and its clinical application.

Development of a low-frequency magnetic lightning mapping system(LFM-LMS)in North China:validation and preliminary results

A low-frequency magnetic lightning mapping system(LFM-LMS)was built during the SHAndong Triggered Lightning Experiment(SHATLE),based on continuous measurements of magnetic field radiation from lightning.The hardware and source-mapping techniques used by the LFM-LMS were introduced;both Monte Carlo simulations and the observation of rocket-triggered lightning examples were employed to examine the location accuracy and detection effectiveness of the LFM-LMS.We estimated that the system’s location accuracy about 100−200 m horizontally and~200 m vertically.A natural intra-cloud lightning flash and a rocket-triggered lightning flash,both with intricate structures and discharging processes,were examined using the three-dimensional mapping results.The progressing path of negative lightning leaders is usually well-defined,and its propagation speed is estimated to be(0.5−1.4)×10^(6)m/s.In summary,the LFM-LMS can reconstruct the three-dimensional morphology of lightning flashes;this technology provides a efficient method for investigating the characteristics of lightning development,as well as the overall electrical strucuture of thunderstorms.

Contribution of glial cells to the neuroprotective effects triggered by repetitive magnetic stimulation:a systematic review

Repetitive transcranial magnetic stimulation has been increasingly studied in different neurological diseases,and although most studies focus on its effects on neuronal cells,the contribution of nonneuronal cells to the improvement trigge red by repetitive transcranial magnetic stimulation in these diseases has been increasingly suggested.To systematically review the effects of repetitive magnetic stimulation on non-neuronal cells two online databases.Web of Science and PubMed were searched fo r the effects of high-frequency-repetitive transcranial magnetic stimulation,low-frequencyrepetitive transcranial magnetic stimulation,intermittent theta-bu rst stimulation,continuous thetaburst stimulation,or repetitive magnetic stimulation on non-neuronal cells in models of disease and in unlesioned animals or cells.A total of 52 studies were included.The protocol more frequently used was high-frequency-repetitive magnetic stimulation,and in models of disease,most studies report that high-frequency-repetitive magnetic stimulation led to a decrease in astrocyte and mic roglial reactivity,a decrease in the release of pro-inflammatory cyto kines,and an increase of oligodendrocyte proliferation.The trend towards decreased microglial and astrocyte reactivity as well as increased oligodendrocyte proliferation occurred with intermittent theta-burst stimulation and continuous theta-burst stimulation.Few papers analyzed the low-frequency-repetitive transcranial magnetic stimulation protocol,and the parameters evaluated were restricted to the study of astrocyte reactivity and release of pro-inflammatory cytokines,repo rting the absence of effects on these paramete rs.In what concerns the use of magnetic stimulation in unlesioned animals or cells,most articles on all four types of stimulation reported a lack of effects.It is also important to point out that the studies were developed mostly in male rodents,not evaluating possible diffe rential effects of repetitive transcranial magnetic stimulation between sexes.This systematic review supports that thro ugh modulation of glial cells repetitive magnetic stimulation contributes to the neuroprotection or repair in various neurological disease models.Howeve r,it should be noted that there are still few articles focusing on the impact of repetitive magnetic stimulation on non-neuronal cells and most studies did not perform in-depth analyses of the effects,emphasizing the need for more studies in this field.

Magnetic nanoparticle-based cancer therapy

Nanoparticles（NPs） with easily modified surfaces have been playing an important role in biomedicine.As cancer is one of the major causes of death,tremendous efforts have been devoted to advance the methods of cancer diagnosis and therapy.Recently,magnetic nanoparticles（MNPs） that are responsive to a magnetic field have shown great promise in cancer therapy.Compared with traditional cancer therapy,magnetic field triggered therapeutic approaches can treat cancer in an unconventional but more effective and safer way.In this review,we will discuss the recent progress in cancer therapies based on MNPs,mainly including magnetic hyperthermia,magnetic specific targeting,magnetically controlled drug delivery,magnetofection,and magnetic switches for controlling cell fate.Some recently developed strategies such as magnetic resonance imaging（MRI） monitoring cancer therapy and magnetic tissue engineering are also addressed.

Endoscopic ultrasound and magnetic resonance imaging for re-staging rectal cancer after radiotherapy

AIM： To compare the sensitivity and specificity of two imaging techniques, endoscopic ultrasound （EUS） and magnetic resonance imaging （MRI）, in patients with rectal cancer after neoadjuvant chemoradiation therapy. And we compared EUS and MRI data with histological findings from surgical specimens. METHODS： Thirty-nine consecutive patients （51.3% Male; mean age： 68.2 ＋ 8.9 years） with histologically confirmed distal rectal cancer were examined for staging. All patients underwent EUS and MRI imaging before and after neoadjuvant chemoradiation therapy. RESULTS： After neoadjuvant chemoradiation, EUS and MRI correctly classified 46% （18/39） and 44% （17/39） of patients, respectively, in line with their histological T stage （P 〉 0.05）. These proportions were higher for both techniques when nodal involvement was considered： 69% （27/39） and 62% （24/39）. When patients were sorted into T and N subgroups, the diagnostic accuracy of EUS was better than MRI for patients with T0-T2 （44% vs 33%, P 〉 0.05） and NO disease （87% vs 52%, P = 0.013）. However, MRI was more accurate than EUS in T and N staging for patients with more advanced disease after radiotherapy, though these differences did not reach statistical significance. CONCLUSION： EUS and MRI are accurate imaging techniques for staging rectal cancer, However, after neoadjuvant RT-CT, the role of both methods in the assessment of residual rectal tumors remains uncertain.

Multifunctional magnetic nanoparticles for magnetic resonance image-guided photothermal therapy for cancer

Key advances in multifunctional magnetic nanoparticles （MNPs） for magnetic resonance （MR） image-guided pho- tothermal therapy of cancer are reviewed. We briefly outline the design and fabrication of such multifunctional MNPs. Bimodal image-guided photothermal therapies （MR/fluorescence and MR/ultrasound） are also discussed.

Low-frequency HIFU induced cancer immunotherapy:tempting challenges and potential opportunities

Immunotherapy is playing an increasingly important role in the treatment of tumors.Different from the traditional direct killing or excision therapies,immunotherapy depends on autologous immunity to kill tumor cells and tissues by activating or enhancing the body's immune system.Large numbers of recent studies suggest that low-frequency HIFU can not only enhance the intensity of the body's anti-cancer immune response,but also improve the efficiency of immunotherapy drug delivery to strengthen the effects of tumor immunotherapy.The focused ultrasound(FUS)destructs the tumor and simultaneously generates tumor debris and tumor-associated antigens,which enhances the immunogenicity of the tumor and stimulates the immune cells,inducing the body's immune response.Microbubbles are clinically used as a contrast.As a matter of fact,the addition of microbubbles can reinforce the destructive effect of FUS on the tumor and activate a stronger immune response.The combined application of ultrasound and microbubbles can more effectively open the blood brain barrier(BBB),which is beneficial to improving the intake of immune cells or immunotherapy drugs and exerting a positive influence in the lesion area.Currently,microbubbles and nanoparticles are commonly used as gene and drug carriers.Using ultrasound,the immune-related gene or antigen delivery itself can enhance the immune response and improve the efficacy of the immunotherapy.

Application of Paclitaxel-loaded EGFR Peptide-conjugated Magnetic Polymeric Liposomes for Liver Cancer Therapy

Developing the methodologies that allow for safe and effective delivery of therapeutic drugs to target sites is a very important research area in cancer therapy.In this study,polyethylene glycol(PEG)-coated magnetic polymeric liposome(MPL)nanoparticles(NPs)assembled from octadecyl quatemized carboxymethyl chitosan(OQC),PEGylated OQC,cholesterol,and magnetic NPs,and functionalized with epithelial growth factor receptor(EGFR)peptide,were successfully prepared for in-vivo liver targeting.The two-step liver targeting strategy,based on both magnetic force and EGFR peptide conjugation,was evaluated in a subcutaneous hepatocellular carcinoma model of nude mouse.The results showed that EGFR-conjugated MPLs not only accumulated in the liver by magnetic force,but could also diffuse into tumor cells as a result of EGFR targeting.In addition,paclitaxel(PTX)was incorporated into small EGFR-conjugated MPLs(102.0土0.7 nm),resulting in spherical particles with high drug encapsulation efficiency(>90%).The use of the magnetic targeting for enhancing the transport of PTX-loaded EGFR-conjugated MPLs to the tumor site was further confirmed by detecting PTX levels.In conclusion,PTX-loaded EGFR-conjugated MPLs could potentially be used as an effective drug delivery system for targeted liver cancer therapy.

Does a combined intervention program of repetitive transcranial magnetic stimulation and intensive occupational therapy affect cognitive function in patients with post-stroke upper limb hemiparesis?

Low-frequency repetitive transcranial magnetic stimulation（LF-r TMS） to the contralesional hemisphere and intensive occupational therapy（i OT） have been shown to contribute to a significant improvement in upper limb hemiparesis in patients with chronic stroke. However, the effect of the combined intervention program of LF-r TMS and i OT on cognitive function is unknown. We retrospectively investigated whether the combined treatment influence patient＇s Trail-Making Test part B（TMT-B） performance, which is a group of easy and inexpensive neuropsychological tests that evaluate several cognitive functions. Twenty-five patients received 11 sessions of LF-r TMS to the contralesional hemisphere and 2 sessions of i OT per day over 15 successive days. Patients with right- and left-sided hemiparesis demonstrated significant improvements in upper limb motor function following the combined intervention program. Only patients with right-sided hemiparesis exhibited improved TMT-B performance following the combined intervention program, and there was a significant negative correlation between Fugl-Meyer Assessment scale total score change and TMT-B performance. The results indicate the possibility that LF-r TMS to the contralesional hemisphere combined with i OT improves the upper limb motor function and cognitive function of patients with right-sided hemiparesis. However, further studies are necessary to elucidate the mechanism of improved cognitive function.

~1H-magnetic resonance spectroscopy screening for animals with acute cerebral infraction suitable forthrombolytic therapy

BACKGROUND： As a non-invasive technique which can provide comprehensive biological information, 1H-magnetic resonance spectroscopy （1H-MRS） may provide valuable reference data for irreversible recovery or reversible changes in ischemic tissue after stroke. OBJECTIVE： To monitor and evaluate the effect of the urokinase thrombolytic therapy after experimental acute cerebral ischemia by 1H-MRS technology and investigate its adaptability. DESIGN： Randomly controlled animal study. SETTINGS： Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom ＆ Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science. MATERIALS： Eleven healthy adult Sprague-Dawley （SD） rats, weighing 260–300 g and of both genders, were supplied by Experimental Animal Center of Tongji Medical Collage, Huazhong University of Science and Technology [SCXK （e） 2004-007]. 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. METHODS： The experiment was carried out in Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom ＆ Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science from August 2003 to December 2005. ① The rats were randomly divided into 30-minute self-thrombo-embolism group （n =6） and 60-minute self-thrombo-embolism group （n =5）. Six rats in 30-minute self-thrombo-embolism group were occluded with clot embolus for 30 minutes and 5 rats in 60-minute self-thrombo-embolism group were occluded for 60 minutes. 10 000 U/kg urokinase was dissolved in 2 mL saline and the operation lasted for 5 minutes. ② 1H-MRS was performed before thrombolysis and at 3 hours and 24 hours after successful embolization. The metabolic changes of N-acetyl-L-aspartic acid （NAA）/phosphocreatine （PCr） ＋ creatine （Cr）, choline phosphate （Cho）/PCr＋Cr and lactic acid （Lac）/PCr＋Cr in the region of interests were analyzed. ③ The T2W image was conducted 24 hours after the thrombolytic therapy with TR=500 ms and TE=25 ms. ④ The subjects were sacrificed immediately after 1H-MRS and the brain tissues were cut into pieces and stained with HE method; in addition, pathological changes were observed under optic microscope. MAIN OUTCOME MEASURES： ① Metabolic changes of NAA/PCr＋Cr, Cho/PCr＋Cr and Lac/PCr＋Cr in the region of interests; ② T2W image at 24 hours after the thrombolysis; ③ pathological observation of brain tissue. RESULTS： Eleven rats were all involved in the final analysis. ① Metabolic changes in the region of interests ： In 30-minute self-thrombo-embolism group, the Lac peak emerged immediately after the embolism, but the ischemic zone decreased 3 hours after the thrombolytic therapy （0.252±0.01, 0.603±0.01, P 〈 0.01）. Lac/（PCr＋Cr） ratio was 0.290±0.01 at 24 hours after thrombolysis, which was higher than that at 3 hours after thrombolysis （P 〈 0.01）. The NAA/ （PCr＋Cr） ratio decreased significantly at 3 hours after the thrombolysis as compared with that before thrombolysis （0.922±0.16, 1.196±0.01, P 〈 0.05）. In 60-minute self-thrombo-embolism group, the Lac/（PCr＋Cr） ratio was higher at 3 hours after thrombolysis than that before thrombolysis （0.846±0.12, 0.601±0.11, P 〈 0.05） and the NAA/（PCr＋Cr） decreased at 3 hours after the embolism. Fluctuation of NAA/ （PCr＋Cr） ranged from 0.68 to 0.75 before thrombolysis and from 0.71 to 0.75 at 3 hours after thrombolysis. ② T2W image： T2W image showed that 2 subjects in 30-minute self-thrombo-embolism group whose Lac/NAA was higher than 0.7 suffered from intracranial hemorrhage. This meant that the subjects with Lac/NAA 〉 0.7 were more likely to suffer from intracranial hemorrhage. ③ Histological and morphological examinations： Optic microscope demonstrated that interspace surrounding nerve cells was widened at ischemic center; neurons were swelling; nucleus was stained lightly; pyknosis and mesenchymal edema were mainly observed in lateral cortex of brow and vertex and in lateralpart of corpus striatum. CONCLUSION： ①Compound parameters in ischemic area before thrombolysis should be regarded as an important predicting marker for thrombolytic therapy, effect evaluation and termination. ② 1H-MRS combining with other imaging technique is a detecting way for screening cases who are suitable for thrombolytic therapy.

Reversible lesions in the brain parenchyma in Wilson's disease confirmed by magnetic resonance imaging:earlier administration of chelating therapy can reduce the damage to the brain

The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson’s disease during the long-term chelating therapy using magnetic resonance imaging and a possible signiifcance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson’s disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into： group A, where chelating therapy was initiated 〈 24 months from the ifrst symp-toms and group B, where the therapy started≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a signiifcant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions （P= 0.005 andP=0.024, respectively）. If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be ex-pected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.

Functionalized magnetic nanoparticles for drug delivery in tumor therapy

The side effects of chemotherapy are mainly the poor control of drug release. Magnetic nanoparticles(MNPs) have super-paramagnetic behaviors which are preferred for biomedical applications such as in targeted drug delivery, besides, in magnetic recording, catalysis, and others. MNPs, due to high magnetization response, can be manipulated by the external magnetic fields to penetrate directly into the tumor, thus they can act as ideal drug carriers. MNPs also play a crucial role in drug delivery system because of their high surface-to-volume ratio and porosity. The drug delivery in tumor therapy is related to the sizes, shapes, and surface coatings of MNPs as carriers. Therefore, in this review, we first summarize the effects of the sizes, shapes, and surface coatings of MNPs on drug delivery, then discuss three types of drug release systems, i.e., p H-controlled, temperature-controlled, and magnetic-controlled drug release systems, and finally compare the principle of passive drug release with that of active drug release in tumor therapy.

Design of a large momentum acceptance proton therapy gantry utilizing AG-CCT magnets

The application of superconducting(SC)technology enables magnets to excite strong fields with small footprints,which has great potential for miniaturizing proton therapy gantries.However,the slow ramping rate of SC magnets results in a low treatment efficiency compared with normal-conducting(NC)gantries.To address this problem,this study proposes a compact proton therapy gantry design with a large momentum acceptance utilizing alternating-gradient canted-cosine-theta(AG-CCT)SC magnets.In our design,a high-transmission degrader is mounted in the middle of the gantry,and the upstream beamline employs NC magnets with small apertures.Downstream of the degrader,large-bore AG-CCT magnets with strong alternating focusing gradients are set symmetrically as a local achromat,which realizes a momentum acceptance of 20%(or 40%in the energy domain).Therefore,only three magnetic working points are required to cover a treatment energy of 70-230 Me V.Owing to the large momentum acceptance,the proton beam after the degrader can be directly delivered to the isocenter without truncating its energy spectrum,which can significantly increase the treatment efficiency but causes severe dispersion effects during pencil beam scanning.Therefore,a compensation method was introduced by tuning the normal and skewed quadrupoles during the scanning process.As a result,the new gantry not only presents a remarkable reduction in the size and weight of the facility but also shows good potential for fast treatment.