Background:To evaluate sex‐related differences in the risk factors associated with nonhealing or recurrence of hyper-thyroidism(NHRH)in patients with Graves'disease(GD)treated with radioactive iodine.Methods:In t...Background:To evaluate sex‐related differences in the risk factors associated with nonhealing or recurrence of hyper-thyroidism(NHRH)in patients with Graves'disease(GD)treated with radioactive iodine.Methods:In total,285 patients were enrolled.Data on radioactive iodine(RAI)dosage,ultrasound indexes of the thyroid,and other clinical factors were collected.Patients were divided into NHRH and non‐NHRH(hypothyroidism or euthyroidism)groups based on treatment outcomes.Univariate and multivariate weighted logistic regression analyses were used to identify factors associated with NHRH.Sex‐specific analyses of these risk factors were also conducted.Results:There were no significant differences between the two groups in terms of sex,thyroid shear wave elastography velocity values,or pretreatment serum free thyroxine(FT4)levels.Thyroid volume and age were independently associated with NHRH,with the odds of NHRH gradually decreasing as age increased.In subgroup analyses,both age and thyroid volume were independent risk factors for NHRH in female patients(p<0.05),while in male patients,only FT4 was independently associated with NHRH(p<0.05).Conclusions:In patients of different sexes,the influence of thyroid volume,age,and FT4 on treatment outcomes exhibits distinct patterns.展开更多
Introduction: In hyperthyroidism, selective irradiation of the thyroid gland with radioactive iodine is a radical treatment and an alternative to surgery. The aim of this review is to assess the medium-term efficacy o...Introduction: In hyperthyroidism, selective irradiation of the thyroid gland with radioactive iodine is a radical treatment and an alternative to surgery. The aim of this review is to assess the medium-term efficacy of outpatient treatment of hyperthyroidism with iodine-131 in Africa. Methods: We identified the studies carried out in Africa on outpatient radiation therapy between 2016 and 2020. For each article included, we noted the country concerned and the year of publication, the numbers studied, the socio-demographic characteristics of the patients, the indications for radio iodine therapy, the dose administered, the results of the hormonal dosage 6 months after radiation. Results: 13 retrospective studies were included to constitute a total population of 925 patients. The average age was 40.77 years, the sex ratio of 1/5.4 with a clear female predominance. The 3 main etiologies of hyperthyroidism justifying outpatient radio iodine therapy were Graves’ disease (55.89%), toxic multinodular goiter (22.70%) and toxic adenoma (21.40%). The average dose of iodine 131 administered per course is 13.7 mCi. No short-and medium-term complications were reported. The radio iodine therapy was effective in 86.08% (n = 796) of the patients with extremes of 72% and 100%. Conclusion: Radio iodine therapy is effective in Africa. It is simple, inexpensive on an outpatient basis and well tolerated. The introduction of outpatient radio iodine therapy could improve the management of patients with hyperthyroidism in Burkina Faso.展开更多
Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for as...Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.展开更多
BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a y...BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a young male who rapidly developed hypothyroid cardiomyopathy secondary to radioactive iodine treatment,suggesting that severe HF might occur even after a short period of hypothyroidism.CASE SUMMARY A 26-year-old man was referred to our hospital for HF presenting with dyspnea on exertion and chest discomfort lasting for 1 mo.He received radioactive iodine treatment for hyperthyroidism 1 year ago and had an almost normal echocardiogram 6 mo ago.Admission echocardiogram and cardiac magnetic resonance(CMR)revealed left ventricle(LV)global hypokinesia and severely depressed systolic function.In addition,late gadolinium enhancement indicated no obvious changes in the myocardium.Thyroid function tests showed decreased serum levels of thyroid hormone(TH)and elevated thyroid-stimulating hormone.Based on an exclusionary examination,the patient was diagnosed with hypothyroid cardiomyopathy and was started on replacement therapy.His HF symptoms were completely relieved during the six-month follow-up,and echocardiogram and CMR revealed recovered LV size and ejection fraction.CONCLUSION This report demonstrates that severe fluctuations in TH levels may lead to acute HF,which can completely recover with timely thyroid hormone replacement.In addition,our findings highlight the importance of routinely detecting cardiac function in patients treated with radioactive iodine.展开更多
In total 184 studies, which included thyroid uptake and scintigraphy, were performed in 68 hyperthyroid patients: 67% female and 33% male to investigate their thyroid conditions. The aim of the present study was to il...In total 184 studies, which included thyroid uptake and scintigraphy, were performed in 68 hyperthyroid patients: 67% female and 33% male to investigate their thyroid conditions. The aim of the present study was to illustrate the role of uptake and scintigraphy tests in determining the thyroid status of hyperthyroid patients. The uptake study was performed by oral administration of 100 - 200 μCi of 131I as sodium-iodide and counting the radioactivity at 2 and 24 hrs, whereas thyroid scintigraphy was performed 20 minutes after an intravenous injection of 2 - 4 mCi of 99mTc-pertechnetate. The present results of thyroid uptake and scintigraphy successfully identified the thyroid condition in different states. The present results were also compared with some reported data and found to be fair in good agreement.展开更多
The study was to evaluate factors affecting outcome of 131I therapy in hyperthyroidism for optimizing the method. Data from 213 patients who received 131I treatment from July 2003 to July 2005 in our department were r...The study was to evaluate factors affecting outcome of 131I therapy in hyperthyroidism for optimizing the method. Data from 213 patients who received 131I treatment from July 2003 to July 2005 in our department were retrospectively analyzed. Factors possibly contributing to the outcome of the 131I therapy were analyzed, including gen-der, age, history of antithyroid drug, thyroid volume, duration of disease and radioactive iodine uptake rate. Multivariate analysis was done. The rates of euthyroidism and hypothyroidism were 69% and 8.5%, respectively, after one time 131I therapy. Multivariate analysis of the patients showed no statistically significant factors affecting the outcome of 131I therapy. The study showed that 131I dose can be directly calculated, and this simplifies the dose-determined method and individualizes the therapy.展开更多
Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 ...Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 years old)were collected and analyzed based on three balance studies in Shenzhen,Yinchuan,and Changzhi.The single exponential equation was accordingly used to simulate the trajectory of 24 h urinary iodine excretion as the low iodine experimental diets offered(iodine intake:11-26μg/day)and to further deduce the dietary reference intakes(DRIs)for iodine,including estimated average requirement(EAR)and recommended nutrient intake(RNI).Results The minimum iodine excretion was estimated as 57,58,and 51μg/day in three balance studies,respectively.Moreover,it was further suggested as 57,58,and 51μg/day for iodine EAR,and 80,81,and 71μg/day for iodine RNI or expressed as 1.42,1.41,and 1.20μg/(day·kg)of body weight.Conclusion The iodine DRIs for Chinese adults were established based on the obligatory iodine loss hypothesis,which provides scientific support for the amendment of nutrient requirements.展开更多
Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of fligh...Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].展开更多
Groundwater is the main water supply source in the Tarim Basin in China.Endemic disease caused by high iodine(I)groundwater in the Tarim Basin was reported previously.Therefore,it is crucial to systematically identify...Groundwater is the main water supply source in the Tarim Basin in China.Endemic disease caused by high iodine(I)groundwater in the Tarim Basin was reported previously.Therefore,it is crucial to systematically identify the distribution and genesis of groundwater I.Based on hydrochemical analysis of 717 groundwater samples collected in 2015–2018,spatial distribution and hydrogeochemistry characteristic of high I groundwater in different aquifers were analyzed.Results showed that groundwater I ranged between<10.00 and 4000.00μg/L(mean of 53.71μg/L).High I groundwater(I>100.00μg/L)accounted for 7.25%of the total samples.Horizontally,groundwater I significantly increased from recharge zone(RZ)to transition zone(TZ)and to evaporation zone(EZ).Vertically,groundwater in shallow confined aquifer(SCA)had the greatest I concentration,followed by single-structure phreatic aquifer(SSPA),phreatic aquifer in confined groundwater area(PACGA),while groundwater in deep confined aquifer(DCA)generally had low I concentration.Groundwater I enrichment in SSPA was mainly affected by organic matter(OM)decomposition and that in SCA was mainly affected by evaporite mineral dissolution,OM decomposition under alkaline environment.While I enrichment in groundwater of PACGA was restrained under neutral environment.Lacustrine sedimentary environment was crucial for I enrichment in groundwater.Besides,fine-grained lithology of aquifer,smooth topographic slope,shallow buried depth of groundwater,weak alkaline and reducing environment,reductive dissolution of iron oxide/hydroxide minerals and OM decomposition were advantageous to I enrichment in groundwater.展开更多
Currently,iodine-compatible cathodes for iodine propulsion systems that can provide ampere-level electron currents with a reasonable power consumption are lacking.In this study,a conventional LaB_(6)hollow cathode mad...Currently,iodine-compatible cathodes for iodine propulsion systems that can provide ampere-level electron currents with a reasonable power consumption are lacking.In this study,a conventional LaB_(6)hollow cathode made with iodine-resistant materials was designed and tested in an iodine-compatible vacuum facility.The ignition characteristics,the V-I(Volt-Ampere characteristic)curve,and long steady-state discharge sequence of the iodine hollow cathode were analyzed and compared with those using a krypton propellant.After the experiment,the composition of the cathode emitter was studied by scanning electron microscope and energy-dispersive X-ray spectroscopy(EDS).The results show that ignition takes>10 s to reach a steady state,and the discharge voltage of the iodine was 25-95 V higher than that of krypton.According to the EDS results,this was mainly caused by emitter contamination with iron from the stainless-steel components of the cathode and oxygen from the iodine feed system.The iodine hollow cathode achieved a cumulative 12.5 h stable discharge,with the longest single discharge of 5 h and a 3%change in the inner diameter of the emitter.展开更多
With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa f...With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa fiber(PTF)and the highly active iodine vapor capture ability of zero-valent silver nanoparticles(PTF@Ag^(0)NP),an Ag^(0)NP composite functional material with highly efficient iodine vapor capture capability was synthesized from biowaste PTF through ultrasonic and hightemperature hydrothermal methods in this study.The iodine capture experiment demonstrated that PTF@Ag^(0)NP exhibits rapid iodine capture efficiency,reaching dynamic equilibrium within 4 h and a maximum capture capacity of 1008.1 mg/g.Density functional theory calculations show that PTF@Ag^(0)NP exhibits extremely high chemical reactivity toward iodine,with a reaction binding energy of-2.88 e V.Additionally,the molecular dynamics of PTF@Ag^(0)NP indicate that there is no atomic displacement at 77?C,indicating the excellent temperature stability of the material at the operating temperature.The capture mechanism suggests that iodine vapor primarily reacts with Ag^(0)NP to form Ag I,and that the hydroxyl groups in PTF can also effectively capture iodine vapor by adsorption induction.In conclusion,PTF@Ag^(0)NP is expected to be an effective candidate adsorbent material for removing radioactive iodine vapor from exhaust gases during spent fuel reprocessing.展开更多
The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I_(2) batteries,but is unclear,retarding further advances.This work innovatively indicat...The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I_(2) batteries,but is unclear,retarding further advances.This work innovatively indicates a great contribution of∼2.5nm pore structure of nanocarbons to efficient iodine adsorption,rapid I^(−)↔I_(2) conversion,and polyiodide inhibition,via scrupulously designing catalysts with controllable pore sizes systematically.The I_(2)-loading within the designed nitrogen-doped nanocarbons can reach up to as high as 60.8 wt%.The batteries based on the cathode deliver impressive performances with a large capacity of 178.8 mAh/g and long-term cycling stability more than 4000 h at 5.0 C.Notably,these is no polyiodide such as I_(3)−and I_(5)−detected during the charge-discharge processes from comprehensive electrochemical cyclic voltammetry,X-ray photoelectron spectroscopy,and Raman technique.This work provides a novel knowledge-guided concept for rational pore design,promising better Zn-I_(2) batteries,which is also hoped to benefit other advanced energy technologies,such as Li-S,Li-ion,and Al-I_(2) batteries.展开更多
We investigated dissolved iodine species in seawater from the northern South China Sea Shelf.Iodide concentrations were determined by cathodic stripping square wave voltammetry,and iodate was measured by spectrophotom...We investigated dissolved iodine species in seawater from the northern South China Sea Shelf.Iodide concentrations were determined by cathodic stripping square wave voltammetry,and iodate was measured by spectrophotometry.Dissolved organic iodine(DOI)was measured with reference to reduced iodide.R-TDI(R-X or rationalized-X is the concentration of X normalized to a salinity of 35,TDI represents total dissolved iodine)was in the range of 0.43–0.46μmol/L,showing a relatively conservative behavior,while iodate,iodide,and DOI showed non-conservative behaviors.Distribution characteristics in the surface waters showed R-iodate values in the 0.28–0.32μmol/L range and an offshore>inshore trend,while R-iodide was in the 0.11–0.19μmol/L range and R-DOI in the 0–0.07μmol/L range,reflecting an inshore>offshore trend for both.The vertical distribution showed the highest R-iodide concentrations in the surface waters and decreased values with depth,reaching less than0.01μmol/L at depths>200 m.R-iodate increased with depth with a measured peak value of 0.43μmol/L.Seawater with high iodate/iodide ratio(up to 2.9)was found in the central upwelling region and gradually decreased to 2.0 far from this center.The relationship between R-iodide and R-iodate among all samples followed the 1:1 relationship with a slope slightly less than 1,indicating that the conversion between iodate and iodide species could not account for the observed changes.This finding also suggests that DOI may be an important participant in the mass balance.A box model was applied to calculate the input and output of iodine species,and the result showed that approximately 8%of iodate(1.50×10~8 mol/a)imported to the shelf sea was reduced.Concomitantly,the amount of iodide and DOI produced in the shelf amounted to 1.07×10~8 mol/a,roughly 14%higher than the input iodide.展开更多
BACKGROUND Although surgery remains the primary treatment for gastric cancer(GC),the identification of effective alternative treatments for individuals for whom surgery is unsuitable holds significance.HER2 overexpres...BACKGROUND Although surgery remains the primary treatment for gastric cancer(GC),the identification of effective alternative treatments for individuals for whom surgery is unsuitable holds significance.HER2 overexpression occurs in approximately 15%-20%of advanced GC cases,directly affecting treatment-related decisions.Spectral-computed tomography(sCT)enables the quantification of material compositions,and sCT iodine concentration parameters have been demonstrated to be useful for the diagnosis of GC and prediction of its invasion depth,angioge-nesis,and response to systemic chemotherapy.No existing report describes the prediction of GC HER2 status through histogram analysis based on sCT iodine maps(IMs).AIM To investigate whether whole-volume histogram analysis of sCT IMs enables the prediction of the GC HER2 status.METHODS This study was performed with data from 101 patients with pathologically confirmed GC who underwent preoperative sCT examinations.Nineteen parameters were extracted via sCT IM histogram analysis:The minimum,maximum,mean,standard deviation,variance,coefficient of variation,skewness,kurtosis,entropy,percentiles(1st,5th,10th,25th,50th,75th,90th,95th,and 99th),and lesion volume.Spearman correlations of the parameters with the HER2 status and clinicopathological parameters were assessed.Receiver operating characteristic curves were used to evaluate the parameters’diagnostic performance.RESULTS Values for the histogram parameters of the maximum,mean,standard deviation,variance,entropy,and percentiles were significantly lower in the HER2+group than in the HER2–group(all P<0.05).The GC differentiation and Lauren classification correlated significantly with the HER2 status of tumor tissue(P=0.001 and 0.023,respectively).The 99th percentile had the largest area under the curve for GC HER2 status identification(0.740),with 76.2%,sensitivity,65.0%specificity,and 67.3%accuracy.All sCT IM histogram parameters correlated positively with the GC HER2 status(r=0.237-0.337,P=0.001-0.017).CONCLUSION Whole-lesion histogram parameters derived from sCT IM analysis,and especially the 99th percentile,can serve as imaging biomarkers of HER2 overexpression in GC.展开更多
Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their ...Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage.展开更多
BACKGROUND Lithium carbonate is used to manage various mood disorders,but it can cause thyroid abnormalities,including goiter,hypothyroidism,and hyperthyroidism.In rare cases,it can lead to giant goiter and subclinica...BACKGROUND Lithium carbonate is used to manage various mood disorders,but it can cause thyroid abnormalities,including goiter,hypothyroidism,and hyperthyroidism.In rare cases,it can lead to giant goiter and subclinical hyperthyroidism,which may require surgical intervention in severe cases.CASE SUMMARY This case represents a rare development of giant goiter and subclinical hyperthyroidism in a schizophrenia patient who was subjected to prolonged lithium carbonate treatment.The enlarged thyroid gland caused pressure on the airway and recurrent laryngeal nerve,which led to respiratory distress,hoarseness,and dysphagia.The immediate danger of suffocation required urgent surgical intervention.In this report,we describe the case of a 41-year-old Chinese woman.This sheds light on the etiology and challenges associated with managing a giant goiter.The patient underwent a subtotal thyroidectomy to relieve airway compression and facilitate airway expansion.Prior to the procedure,the patient was given iodine to prepare.Concurrently,changes were made to the psychiatric medication regimen.Following surgery,the patient's respiratory function and vocal cord functionality improved significantly,and her mental state remained stable.CONCLUSION It is essential to monitor thyroid function,test thyroid antibody levels,and perform thyroid ultrasounds consistently in all patients undergoing long-term lithium carbonate treatment.This vigilance helps prevent severe and potentially life-threatening thyroid enlargement.展开更多
Dynamic covalent imine reactions between 2,3-dimethoxy-[1,1:4,1-terphenyl]-3,3,5,5-tetracarbaldehyde(DMTT)and cyclohexanediamine,p-phenylenediamine,and benzidine,respectively,generate a porous organic cage(DMPOC)and t...Dynamic covalent imine reactions between 2,3-dimethoxy-[1,1:4,1-terphenyl]-3,3,5,5-tetracarbaldehyde(DMTT)and cyclohexanediamine,p-phenylenediamine,and benzidine,respectively,generate a porous organic cage(DMPOC)and two covalent organic frameworks(COFs),USTB-29,and USTB-30.DMPOC shows a[3+6]topological cage-like structure according to single crystal X-ray diffraction result.In contrast,both microcrystalline USTB-29 and USTB-30 exhibit two-dimensional monoporous structures in an eclipsed AA stacking style based on powder X-ray diffraction and theoretical simulations.In addition,DMPOC is capable of efficiently absorbing the iodine vapor with an outstanding uptake of 5.10 g/g,much higher than that of USTB-29(3.07 g/g)and USTB-30(3.16 g/g).Cage to COFs transformations have been realized from DMPOC to USTB-29 and USTB-30 via the imine bond exchange with slightly increased iodine vapor uptake.Mechanism investigations uncover that both nitrogen and oxygen atoms of POC and COFs contribute to iodine vapor capture due to the formation of charge transfer matter,and loose interaction introducing adaptive expanding voids of DMPOC is suggested to capture more iodine vapor than that of COFs with strongπ-πinteractions.展开更多
Iodine is an essential trace element for human health.The thyroid gland uses iodine for the synthesis of thyroid hormones.Most iodine comes from food and drinking water,and approximately 85%is excreted through the uri...Iodine is an essential trace element for human health.The thyroid gland uses iodine for the synthesis of thyroid hormones.Most iodine comes from food and drinking water,and approximately 85%is excreted through the urine.Therefore,urinary iodine content is an important indicator for judging the iodine nutrition level of a population[1].A thyroid nodule is a discrete mass resulting from the abnormal proliferation of thyroid cells.Iodine deficiency in the general population has dramatically diminished after implementing universal salt iodization(USI)policies.However,the incidence of thyroid nodules has been reported to be increasing following the implementation of USI,leading some to question the plausibility of USI.This data from Zhao et al.展开更多
In North China,iodine-rich groundwater has been extensively studied,but few in South China.This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamina...In North China,iodine-rich groundwater has been extensively studied,but few in South China.This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamination sources.The results revealed that the average concentration of iodine in groundwater was 890μg/L,with a maximumconcentration of 6350μg/L,exceeding the permitted levels recommended by the World Health Organization(5–300μg/L).Notably,the enrichment of iodide occurred in acidic conditions(pH=6.6)and a relatively low Eh environment(Eh=198.4 mV).Pearson correlation and cluster analyses suggested that the enrichment of iodide could be attributed to the intensified redox process involving Mn(II),iodine(I_(2)),or iodate(IO_(3)^(−))in the soil.The strong affinity between Mn(II)and I_(2)/IO_(3)^(−)facilitated their interaction,resulting in the formation and mobilization of I^(−)from the soil to the groundwater.Leaching experiments further confirmed that reducing substances(such as sodium sulfides,ascorbic acids,and fulvic acids)in the soil with low dissolved oxygen(DO)levels(<1.0 mg/L)enhanced the dissolution of iodine species.Conversely,higher DO content(>3.8 mg/L)promoted the oxidation of I^(−)into I_(2)or IO_(3)^(−),leading to its stabilization.This research provides new insights into the characteristics and mechanisms of I^(−)enrichment in groundwater in South China,and emphasizes the significance of the redox reactions involving Mn(II)and I_(2)/IO_(3)^(−),as well as the influence of soil properties in regulating the occurrence and transportation of iodine species within groundwater systems.展开更多
The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability,...The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability, low vapor pressure, and ionization potential. The performance of a lowpower iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor's mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate.At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are7.19 and 7.58 m N, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8%and 14.5%, and thrust to power ratios are 35.9 and 37.9 m N/k W under the conditions of 250 V,0.8 A and 200 V, 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.展开更多
基金suported by the National High Level Hospital Clinical Research Funding(2022-NHLHCRF-LX-02-03,2023-NHLHCRF-YXHZ-ZRZD-06)Ministry ofScience and Technology of the People's Republic ofChina,and National Natural Science Foundation ofChina(82071943,82273523).
文摘Background:To evaluate sex‐related differences in the risk factors associated with nonhealing or recurrence of hyper-thyroidism(NHRH)in patients with Graves'disease(GD)treated with radioactive iodine.Methods:In total,285 patients were enrolled.Data on radioactive iodine(RAI)dosage,ultrasound indexes of the thyroid,and other clinical factors were collected.Patients were divided into NHRH and non‐NHRH(hypothyroidism or euthyroidism)groups based on treatment outcomes.Univariate and multivariate weighted logistic regression analyses were used to identify factors associated with NHRH.Sex‐specific analyses of these risk factors were also conducted.Results:There were no significant differences between the two groups in terms of sex,thyroid shear wave elastography velocity values,or pretreatment serum free thyroxine(FT4)levels.Thyroid volume and age were independently associated with NHRH,with the odds of NHRH gradually decreasing as age increased.In subgroup analyses,both age and thyroid volume were independent risk factors for NHRH in female patients(p<0.05),while in male patients,only FT4 was independently associated with NHRH(p<0.05).Conclusions:In patients of different sexes,the influence of thyroid volume,age,and FT4 on treatment outcomes exhibits distinct patterns.
文摘Introduction: In hyperthyroidism, selective irradiation of the thyroid gland with radioactive iodine is a radical treatment and an alternative to surgery. The aim of this review is to assess the medium-term efficacy of outpatient treatment of hyperthyroidism with iodine-131 in Africa. Methods: We identified the studies carried out in Africa on outpatient radiation therapy between 2016 and 2020. For each article included, we noted the country concerned and the year of publication, the numbers studied, the socio-demographic characteristics of the patients, the indications for radio iodine therapy, the dose administered, the results of the hormonal dosage 6 months after radiation. Results: 13 retrospective studies were included to constitute a total population of 925 patients. The average age was 40.77 years, the sex ratio of 1/5.4 with a clear female predominance. The 3 main etiologies of hyperthyroidism justifying outpatient radio iodine therapy were Graves’ disease (55.89%), toxic multinodular goiter (22.70%) and toxic adenoma (21.40%). The average dose of iodine 131 administered per course is 13.7 mCi. No short-and medium-term complications were reported. The radio iodine therapy was effective in 86.08% (n = 796) of the patients with extremes of 72% and 100%. Conclusion: Radio iodine therapy is effective in Africa. It is simple, inexpensive on an outpatient basis and well tolerated. The introduction of outpatient radio iodine therapy could improve the management of patients with hyperthyroidism in Burkina Faso.
基金supported by the National Natural Science Foundation of China(Grant numbers 82204041)Gansu Provincial Science and Technology Program Funded Projects(Grant numbers 22JR11RA184).
文摘Iodine is an essential element for the synthesis of thyroid hormones.Iodine deficiency increases the burden on thyroid function and causes harm to health.The identification of convenient and reliable biomarkers for assessing iodine nutritional status is essential for evaluating iodine intake.Urinary iodine concentration(UIC)is commonly used for population level iodine status assessment but is less reliable for individuals.A 24-h urine sample is more accurate but difficult to collect[1].Thyroid volume(Tvol)and goiter rate are suitable for evaluating the long-term iodine nutritional status in populations[2].Blood indicator collection is an invasive procedure.
基金Science and Technology of Jilin Province,No.20200801076GH.
文摘BACKGROUND The deterioration of thyroid health is involved in the progression of heart failure(HF).This is usually a lengthy process,so there are almost no reports on its rapid development.Here we report a case of a young male who rapidly developed hypothyroid cardiomyopathy secondary to radioactive iodine treatment,suggesting that severe HF might occur even after a short period of hypothyroidism.CASE SUMMARY A 26-year-old man was referred to our hospital for HF presenting with dyspnea on exertion and chest discomfort lasting for 1 mo.He received radioactive iodine treatment for hyperthyroidism 1 year ago and had an almost normal echocardiogram 6 mo ago.Admission echocardiogram and cardiac magnetic resonance(CMR)revealed left ventricle(LV)global hypokinesia and severely depressed systolic function.In addition,late gadolinium enhancement indicated no obvious changes in the myocardium.Thyroid function tests showed decreased serum levels of thyroid hormone(TH)and elevated thyroid-stimulating hormone.Based on an exclusionary examination,the patient was diagnosed with hypothyroid cardiomyopathy and was started on replacement therapy.His HF symptoms were completely relieved during the six-month follow-up,and echocardiogram and CMR revealed recovered LV size and ejection fraction.CONCLUSION This report demonstrates that severe fluctuations in TH levels may lead to acute HF,which can completely recover with timely thyroid hormone replacement.In addition,our findings highlight the importance of routinely detecting cardiac function in patients treated with radioactive iodine.
文摘In total 184 studies, which included thyroid uptake and scintigraphy, were performed in 68 hyperthyroid patients: 67% female and 33% male to investigate their thyroid conditions. The aim of the present study was to illustrate the role of uptake and scintigraphy tests in determining the thyroid status of hyperthyroid patients. The uptake study was performed by oral administration of 100 - 200 μCi of 131I as sodium-iodide and counting the radioactivity at 2 and 24 hrs, whereas thyroid scintigraphy was performed 20 minutes after an intravenous injection of 2 - 4 mCi of 99mTc-pertechnetate. The present results of thyroid uptake and scintigraphy successfully identified the thyroid condition in different states. The present results were also compared with some reported data and found to be fair in good agreement.
文摘The study was to evaluate factors affecting outcome of 131I therapy in hyperthyroidism for optimizing the method. Data from 213 patients who received 131I treatment from July 2003 to July 2005 in our department were retrospectively analyzed. Factors possibly contributing to the outcome of the 131I therapy were analyzed, including gen-der, age, history of antithyroid drug, thyroid volume, duration of disease and radioactive iodine uptake rate. Multivariate analysis was done. The rates of euthyroidism and hypothyroidism were 69% and 8.5%, respectively, after one time 131I therapy. Multivariate analysis of the patients showed no statistically significant factors affecting the outcome of 131I therapy. The study showed that 131I dose can be directly calculated, and this simplifies the dose-determined method and individualizes the therapy.
基金supported by the National Natural Science Foundation of China(Grant No.81872624)Fundamental Research Program of Shanxi Province(Grant No.202403021211139).
文摘Objective This study aimed to reexplore minimum iodine excretion and to build a dietary iodine recommendation for Chinese adults using the obligatory iodine loss hypothesis.Methods Data from 171 Chinese adults(19–21 years old)were collected and analyzed based on three balance studies in Shenzhen,Yinchuan,and Changzhi.The single exponential equation was accordingly used to simulate the trajectory of 24 h urinary iodine excretion as the low iodine experimental diets offered(iodine intake:11-26μg/day)and to further deduce the dietary reference intakes(DRIs)for iodine,including estimated average requirement(EAR)and recommended nutrient intake(RNI).Results The minimum iodine excretion was estimated as 57,58,and 51μg/day in three balance studies,respectively.Moreover,it was further suggested as 57,58,and 51μg/day for iodine EAR,and 80,81,and 71μg/day for iodine RNI or expressed as 1.42,1.41,and 1.20μg/(day·kg)of body weight.Conclusion The iodine DRIs for Chinese adults were established based on the obligatory iodine loss hypothesis,which provides scientific support for the amendment of nutrient requirements.
基金supported by the Military Medical Science and Technology Youth Cultivation Program of the Chinese PLA(17QNP023)the Key Projects of Medical Service Scientific Research of the Navy Medical Center(20M2302)the Military Logistics National Military Standard General Project of Chinese PLA(BHJ22B002).
文摘Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].
基金financially supported by the National Natural Science Foundation of China(Nos.42067035 and 42007161)Water Conservancy Engineering Key Discipline Project of Xinjiang Agricultural University(No.SLXK2019-10)the Opening Project of Xinjiang Key Laboratory of Hydraulic Engineering Security and Water Disasters Prevention in 2021(No.ZDSYS-JS-2021-10)。
文摘Groundwater is the main water supply source in the Tarim Basin in China.Endemic disease caused by high iodine(I)groundwater in the Tarim Basin was reported previously.Therefore,it is crucial to systematically identify the distribution and genesis of groundwater I.Based on hydrochemical analysis of 717 groundwater samples collected in 2015–2018,spatial distribution and hydrogeochemistry characteristic of high I groundwater in different aquifers were analyzed.Results showed that groundwater I ranged between<10.00 and 4000.00μg/L(mean of 53.71μg/L).High I groundwater(I>100.00μg/L)accounted for 7.25%of the total samples.Horizontally,groundwater I significantly increased from recharge zone(RZ)to transition zone(TZ)and to evaporation zone(EZ).Vertically,groundwater in shallow confined aquifer(SCA)had the greatest I concentration,followed by single-structure phreatic aquifer(SSPA),phreatic aquifer in confined groundwater area(PACGA),while groundwater in deep confined aquifer(DCA)generally had low I concentration.Groundwater I enrichment in SSPA was mainly affected by organic matter(OM)decomposition and that in SCA was mainly affected by evaporite mineral dissolution,OM decomposition under alkaline environment.While I enrichment in groundwater of PACGA was restrained under neutral environment.Lacustrine sedimentary environment was crucial for I enrichment in groundwater.Besides,fine-grained lithology of aquifer,smooth topographic slope,shallow buried depth of groundwater,weak alkaline and reducing environment,reductive dissolution of iron oxide/hydroxide minerals and OM decomposition were advantageous to I enrichment in groundwater.
基金supported by the National Key R&D Program of China(No.2022YFE0204100)the Key Program of University-Enterprise Joint Project of National Natural Science Foundation of China(No.U22B20120).
文摘Currently,iodine-compatible cathodes for iodine propulsion systems that can provide ampere-level electron currents with a reasonable power consumption are lacking.In this study,a conventional LaB_(6)hollow cathode made with iodine-resistant materials was designed and tested in an iodine-compatible vacuum facility.The ignition characteristics,the V-I(Volt-Ampere characteristic)curve,and long steady-state discharge sequence of the iodine hollow cathode were analyzed and compared with those using a krypton propellant.After the experiment,the composition of the cathode emitter was studied by scanning electron microscope and energy-dispersive X-ray spectroscopy(EDS).The results show that ignition takes>10 s to reach a steady state,and the discharge voltage of the iodine was 25-95 V higher than that of krypton.According to the EDS results,this was mainly caused by emitter contamination with iron from the stainless-steel components of the cathode and oxygen from the iodine feed system.The iodine hollow cathode achieved a cumulative 12.5 h stable discharge,with the longest single discharge of 5 h and a 3%change in the inner diameter of the emitter.
基金supported by the Sichuan Outstanding Young Scientific and Technological Talents Project(No.2021JDJQ0016)Doctoral Initiation Project of China West Normal University(No.22k E043)and Science and Technology Project of Sichuan Province(No.2022NSFSC0388)。
文摘With the rapid development of nuclear energy,the removal of radioactive iodine generated during spent fuel reprocessing has become increasingly important.Based on the unique straw-like structure of populus tomentosa fiber(PTF)and the highly active iodine vapor capture ability of zero-valent silver nanoparticles(PTF@Ag^(0)NP),an Ag^(0)NP composite functional material with highly efficient iodine vapor capture capability was synthesized from biowaste PTF through ultrasonic and hightemperature hydrothermal methods in this study.The iodine capture experiment demonstrated that PTF@Ag^(0)NP exhibits rapid iodine capture efficiency,reaching dynamic equilibrium within 4 h and a maximum capture capacity of 1008.1 mg/g.Density functional theory calculations show that PTF@Ag^(0)NP exhibits extremely high chemical reactivity toward iodine,with a reaction binding energy of-2.88 e V.Additionally,the molecular dynamics of PTF@Ag^(0)NP indicate that there is no atomic displacement at 77?C,indicating the excellent temperature stability of the material at the operating temperature.The capture mechanism suggests that iodine vapor primarily reacts with Ag^(0)NP to form Ag I,and that the hydroxyl groups in PTF can also effectively capture iodine vapor by adsorption induction.In conclusion,PTF@Ag^(0)NP is expected to be an effective candidate adsorbent material for removing radioactive iodine vapor from exhaust gases during spent fuel reprocessing.
基金supported by the Tianjin Natural Science Foundation of China(Nos.20JCZDJC00280 and 20JCYBJC00380).
文摘The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I_(2) batteries,but is unclear,retarding further advances.This work innovatively indicates a great contribution of∼2.5nm pore structure of nanocarbons to efficient iodine adsorption,rapid I^(−)↔I_(2) conversion,and polyiodide inhibition,via scrupulously designing catalysts with controllable pore sizes systematically.The I_(2)-loading within the designed nitrogen-doped nanocarbons can reach up to as high as 60.8 wt%.The batteries based on the cathode deliver impressive performances with a large capacity of 178.8 mAh/g and long-term cycling stability more than 4000 h at 5.0 C.Notably,these is no polyiodide such as I_(3)−and I_(5)−detected during the charge-discharge processes from comprehensive electrochemical cyclic voltammetry,X-ray photoelectron spectroscopy,and Raman technique.This work provides a novel knowledge-guided concept for rational pore design,promising better Zn-I_(2) batteries,which is also hoped to benefit other advanced energy technologies,such as Li-S,Li-ion,and Al-I_(2) batteries.
基金The Zhangzhou National Science Foundation of Fujian under contract No.JJ2020J29。
文摘We investigated dissolved iodine species in seawater from the northern South China Sea Shelf.Iodide concentrations were determined by cathodic stripping square wave voltammetry,and iodate was measured by spectrophotometry.Dissolved organic iodine(DOI)was measured with reference to reduced iodide.R-TDI(R-X or rationalized-X is the concentration of X normalized to a salinity of 35,TDI represents total dissolved iodine)was in the range of 0.43–0.46μmol/L,showing a relatively conservative behavior,while iodate,iodide,and DOI showed non-conservative behaviors.Distribution characteristics in the surface waters showed R-iodate values in the 0.28–0.32μmol/L range and an offshore>inshore trend,while R-iodide was in the 0.11–0.19μmol/L range and R-DOI in the 0–0.07μmol/L range,reflecting an inshore>offshore trend for both.The vertical distribution showed the highest R-iodide concentrations in the surface waters and decreased values with depth,reaching less than0.01μmol/L at depths>200 m.R-iodate increased with depth with a measured peak value of 0.43μmol/L.Seawater with high iodate/iodide ratio(up to 2.9)was found in the central upwelling region and gradually decreased to 2.0 far from this center.The relationship between R-iodide and R-iodate among all samples followed the 1:1 relationship with a slope slightly less than 1,indicating that the conversion between iodate and iodide species could not account for the observed changes.This finding also suggests that DOI may be an important participant in the mass balance.A box model was applied to calculate the input and output of iodine species,and the result showed that approximately 8%of iodate(1.50×10~8 mol/a)imported to the shelf sea was reduced.Concomitantly,the amount of iodide and DOI produced in the shelf amounted to 1.07×10~8 mol/a,roughly 14%higher than the input iodide.
基金Supported by Science and Technology Program of Fujian Province,No.2021J01430Joint Funds for the Innovation of Science and Technology of Fujian Province,No.2021Y9229.
文摘BACKGROUND Although surgery remains the primary treatment for gastric cancer(GC),the identification of effective alternative treatments for individuals for whom surgery is unsuitable holds significance.HER2 overexpression occurs in approximately 15%-20%of advanced GC cases,directly affecting treatment-related decisions.Spectral-computed tomography(sCT)enables the quantification of material compositions,and sCT iodine concentration parameters have been demonstrated to be useful for the diagnosis of GC and prediction of its invasion depth,angioge-nesis,and response to systemic chemotherapy.No existing report describes the prediction of GC HER2 status through histogram analysis based on sCT iodine maps(IMs).AIM To investigate whether whole-volume histogram analysis of sCT IMs enables the prediction of the GC HER2 status.METHODS This study was performed with data from 101 patients with pathologically confirmed GC who underwent preoperative sCT examinations.Nineteen parameters were extracted via sCT IM histogram analysis:The minimum,maximum,mean,standard deviation,variance,coefficient of variation,skewness,kurtosis,entropy,percentiles(1st,5th,10th,25th,50th,75th,90th,95th,and 99th),and lesion volume.Spearman correlations of the parameters with the HER2 status and clinicopathological parameters were assessed.Receiver operating characteristic curves were used to evaluate the parameters’diagnostic performance.RESULTS Values for the histogram parameters of the maximum,mean,standard deviation,variance,entropy,and percentiles were significantly lower in the HER2+group than in the HER2–group(all P<0.05).The GC differentiation and Lauren classification correlated significantly with the HER2 status of tumor tissue(P=0.001 and 0.023,respectively).The 99th percentile had the largest area under the curve for GC HER2 status identification(0.740),with 76.2%,sensitivity,65.0%specificity,and 67.3%accuracy.All sCT IM histogram parameters correlated positively with the GC HER2 status(r=0.237-0.337,P=0.001-0.017).CONCLUSION Whole-lesion histogram parameters derived from sCT IM analysis,and especially the 99th percentile,can serve as imaging biomarkers of HER2 overexpression in GC.
基金financially supported by National Natural Science Foundation of China(No.22178143)Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515110365 and2020B1515120036)+3 种基金Natural Science Foundation of Anhui Higher Education Institutions(No.2023AH050168)Innovation and Entrepreneurship Training Program for China College Students(No.202310878049)Director Foundation of Anhui Province Engineering Laboratory of Advanced Building Materials(No.JZCL2305ZR)Ph.D.Startup Foundation of Anhui Jianzhu University(No.2023QDZ34)。
文摘Hypercrosslinked polymers(HCPs)with large surface areas,high intrinsic porosities and low production costs may be available platforms for iodine capture.However,the lack of iodine-philicity binding sites limits their adsorption capacity.Here we use vapor-phase postsynthetic amination strategy to introduce electron-donating amino groups into the prefabricated HCPs for enhancing their iodine capture performance.Through simple vapor-phase exposure,the halogen-containing HCPs can be grafted by amines through nucleophilic substitution toward chloro groups.Combining with the abundant amino groups and high porosities,the amino-functionalized porous polymers show substantially increased iodine adsorption capacity,about 221%as that of original one,accompanied by excellent recyclability.Mechanism investigations reveal the key roles of the electron-donor amino groups andπ-conjugated benzene rings along with structure characteristics of porous polymer frameworks in iodine capture.Moreover,this vapor-phase amination strategy shows good generality and can be extended to various amines,e.g.,ethylenediamine,1,3-diaminopropane and diethylenetriamine.Our work proves that this simple vapor-phase postsynthetic functionalization strategy may be applied in other porous polymers with wide application prospects in adsorption,separation and storage.
文摘BACKGROUND Lithium carbonate is used to manage various mood disorders,but it can cause thyroid abnormalities,including goiter,hypothyroidism,and hyperthyroidism.In rare cases,it can lead to giant goiter and subclinical hyperthyroidism,which may require surgical intervention in severe cases.CASE SUMMARY This case represents a rare development of giant goiter and subclinical hyperthyroidism in a schizophrenia patient who was subjected to prolonged lithium carbonate treatment.The enlarged thyroid gland caused pressure on the airway and recurrent laryngeal nerve,which led to respiratory distress,hoarseness,and dysphagia.The immediate danger of suffocation required urgent surgical intervention.In this report,we describe the case of a 41-year-old Chinese woman.This sheds light on the etiology and challenges associated with managing a giant goiter.The patient underwent a subtotal thyroidectomy to relieve airway compression and facilitate airway expansion.Prior to the procedure,the patient was given iodine to prepare.Concurrently,changes were made to the psychiatric medication regimen.Following surgery,the patient's respiratory function and vocal cord functionality improved significantly,and her mental state remained stable.CONCLUSION It is essential to monitor thyroid function,test thyroid antibody levels,and perform thyroid ultrasounds consistently in all patients undergoing long-term lithium carbonate treatment.This vigilance helps prevent severe and potentially life-threatening thyroid enlargement.
基金financially supported by the Natural Science Foundation of China(Nos.22235001,22175020,22131005,and 22261132512)Xiaomi Young Scholar Program+1 种基金the Fundamental Research Funds for the Central UniversitiesUniversity of Science and Technology Beijing。
文摘Dynamic covalent imine reactions between 2,3-dimethoxy-[1,1:4,1-terphenyl]-3,3,5,5-tetracarbaldehyde(DMTT)and cyclohexanediamine,p-phenylenediamine,and benzidine,respectively,generate a porous organic cage(DMPOC)and two covalent organic frameworks(COFs),USTB-29,and USTB-30.DMPOC shows a[3+6]topological cage-like structure according to single crystal X-ray diffraction result.In contrast,both microcrystalline USTB-29 and USTB-30 exhibit two-dimensional monoporous structures in an eclipsed AA stacking style based on powder X-ray diffraction and theoretical simulations.In addition,DMPOC is capable of efficiently absorbing the iodine vapor with an outstanding uptake of 5.10 g/g,much higher than that of USTB-29(3.07 g/g)and USTB-30(3.16 g/g).Cage to COFs transformations have been realized from DMPOC to USTB-29 and USTB-30 via the imine bond exchange with slightly increased iodine vapor uptake.Mechanism investigations uncover that both nitrogen and oxygen atoms of POC and COFs contribute to iodine vapor capture due to the formation of charge transfer matter,and loose interaction introducing adaptive expanding voids of DMPOC is suggested to capture more iodine vapor than that of COFs with strongπ-πinteractions.
基金sponsored by the Fujian Provincial Health Technology Project [2020CXA020]Fujian Provincial Natural Science Funding [2018J01120]
文摘Iodine is an essential trace element for human health.The thyroid gland uses iodine for the synthesis of thyroid hormones.Most iodine comes from food and drinking water,and approximately 85%is excreted through the urine.Therefore,urinary iodine content is an important indicator for judging the iodine nutrition level of a population[1].A thyroid nodule is a discrete mass resulting from the abnormal proliferation of thyroid cells.Iodine deficiency in the general population has dramatically diminished after implementing universal salt iodization(USI)policies.However,the incidence of thyroid nodules has been reported to be increasing following the implementation of USI,leading some to question the plausibility of USI.This data from Zhao et al.
基金supported by the National Key Research and Development Program of China(No.2019YFC1803900)and the 111 Project(No.B18060)as well as Shenzhen Municipal Science and Technology Plan Project(No.JCYJ20160519095007940).
文摘In North China,iodine-rich groundwater has been extensively studied,but few in South China.This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamination sources.The results revealed that the average concentration of iodine in groundwater was 890μg/L,with a maximumconcentration of 6350μg/L,exceeding the permitted levels recommended by the World Health Organization(5–300μg/L).Notably,the enrichment of iodide occurred in acidic conditions(pH=6.6)and a relatively low Eh environment(Eh=198.4 mV).Pearson correlation and cluster analyses suggested that the enrichment of iodide could be attributed to the intensified redox process involving Mn(II),iodine(I_(2)),or iodate(IO_(3)^(−))in the soil.The strong affinity between Mn(II)and I_(2)/IO_(3)^(−)facilitated their interaction,resulting in the formation and mobilization of I^(−)from the soil to the groundwater.Leaching experiments further confirmed that reducing substances(such as sodium sulfides,ascorbic acids,and fulvic acids)in the soil with low dissolved oxygen(DO)levels(<1.0 mg/L)enhanced the dissolution of iodine species.Conversely,higher DO content(>3.8 mg/L)promoted the oxidation of I^(−)into I_(2)or IO_(3)^(−),leading to its stabilization.This research provides new insights into the characteristics and mechanisms of I^(−)enrichment in groundwater in South China,and emphasizes the significance of the redox reactions involving Mn(II)and I_(2)/IO_(3)^(−),as well as the influence of soil properties in regulating the occurrence and transportation of iodine species within groundwater systems.
基金supported by Joint Fund for Equipment Preresearch and Aerospace Science and Technology (No. 6141B061203)。
文摘The common propellants used for electric thrusters, such as xenon and krypton, are rare, expensive,and difficult to acquire. Solid iodine attracts much attention with the advantages of low cost,extensive availability, low vapor pressure, and ionization potential. The performance of a lowpower iodine-fed Hall thruster matched with a xenon-fed cathode is investigated across a broad range of operation conditions. Regulation of the iodine vapor's mass flow rates is stably achieved by using a temperature control method of the iodine reservoir. The thrust measurements are finished utilizing a thrust target during the tests. Results show that thrust and anode-specific impulse increase approximately linearly with the increasing iodine mass flow rate.At the nominal power of 200 W class, iodine mass flow rates are 0.62 and 0.93 mg/s, thrusts are7.19 and 7.58 m N, anode specific impulses are 1184 and 826 s, anode efficiencies are 20.8%and 14.5%, and thrust to power ratios are 35.9 and 37.9 m N/k W under the conditions of 250 V,0.8 A and 200 V, 1.0 A, respectively. The operating characteristics of iodine-fed Hall thruster are analyzed in different states. Further work on the measurements of plasma characteristics and experimental optimization will be carried out.
