Insights into stem cell therapy for diabetic retinopathy: a bibliometric and visual analysis

Stem cells have been confirmed to be involved in the occurrence and development of diabetic retinopathy;however,the underlying mechanisms remain unclear.In this study,we used Citespace software to visually analyze 552 articles exploring the stem cell-based treatment of diabetic retinopathy over the past 20 years,which were included in the Web of Science Core Collection.We found the following:(1)a co-citation analysis of the references cited by all 552 articles indicated 15 clusters.In cluster#0,representing the stem cell field,some highly cited landmark studies emerged between 2009–2013.For example,endothelial progenitor cells and diabetic retinopathy gradually received the full attention of scholars,in terms of their relationship and therapeutic prospects.Some researchers also verified the potential of adipose-derived stem cells to differentiate into stable retinal perivascular cells,using a variety of animal models of retinal vascular disease.All of these achievements provided references for the subsequent stem cell research.(2)An analysis of popular keywords among the 552 articles revealed that,during the past 20 years,a relative increase in basic research articles examining stem cells and endothelial progenitor cells for the treatment of diabetic retinopathy was observed.The contents of these articles primarily involved the expression of vascular endothelial growth factor,vascular regeneration,oxidative stress,and inflammatory response.(3)A burst analysis of keywords used in the 552 articles indicated that genetic and cytological research regarding the promotion of angiogenesis was an issue of concern from 2001 to 2012,including several studies addressing the expression of various growth factor genes;from 2014 to 2020,mouse models of diabetic retinopathy were recognized as mature animal models,and the most recent research has focused on macular degeneration,macular edema,neurodegeneration,and inflammatory changes in diabetic animal models.(4)Globally,the current authoritative studies have focused on basic research towards the stem cell treatment of diabetic retinopathy.Existing clinical studies are of low quality and have insufficient evidence levels,and their findings have not yet been widely accepted in clinical practice.Major challenges during stem cell transplantation remain,including stem cell heterogeneity,cell delivery,and the effective homing of stem cells to damaged tissue.However,clinical trials examining potential stem cell-based treatments of diabetic retinopathy,including the use of pluripotent stem cells,retinal pigment epithelial cells,bone marrow mesenchymal stem cells,and endothelial progenitor cells,are currently ongoing,and high-quality clinical evidence is likely to appear in the future,to promote clinical transformation.

Effect of different deformation and annealing procedures on non-magnetic textured Cu_(60)Ni_(40) alloy substrates

In this work,a series of specimens was prepared by the casting method.Sharp cube-textured substrates were processed by heavy cold rolling and recrystallization annealing(i.e.,the rolling-assisted biaxially textured substrates(RABi TS) method).Both the rolling and the recrystallization texture in the alloy tapes were investigated by X-ray diffraction and electron back-scatter diffraction,respectively.The results showed that a strong copper-type deformation texture was obtained in the heavy cold-rolled substrate.In addition,the recrystallization annealing process was found to be very important for the texture transition in the Cu–Ni alloy substrates.The cube texture content in the Cu60 Ni40 alloy substrates reached 99.7%(≤10°) after optimization of the cold-rolling procedure and the recrystallizing heat-treatment process,whereas the content of low-angle grain boundaries(from 2° to 10° misorientation) in the substrate reached 95.1%.

Present situation of minimally invasive surgical treatment for early gastric cancer

Minimally invasive surgery is a kind of surgical operation,which is performed by using professional surgical instruments and equipment to inactivate,resect,repair or reconstruct the pathological changes,deformities and wounds in human body through micro-trauma or micro-approach,in order to achieve the goal of treatment,its surgical effect is equivalent to the traditional open surgery,while avoiding the morbidity of conventional surgical wounds.In addition,it also has the advantages of less trauma,less blood loss during operation,less psychological burden and quick recovery on patients,and these minimally invasive techniques provide unique value for the examination and treatment of gastric cancer patients.Surgical minimally invasive surgical techniques have developed rapidly and offer numerous options for the treatment of early gastric cancer(EGC):endoscopic mucosal resection(EMR),underwater EMR(UEMR),endoscopic submucosal dissection(ESD),endoscopic full-thickness resection(EFTR),endoscopic submu-cosal excavation(ESE),submucosal tunnel endoscopic resection,laparoscopic and endoscopic cooperative surgery(LECS);Among them,EMR,EFTR and LECS technologies have a wide range of applications and different modific-ations have been derived from their respective surgical operations,such as band-assisted EMR(BA-EMR),conven-tional EMR(CEMR),over-the-scope clip-assisted EFTR,no-touch EFTR,the inverted LECS,closed LECS,and so on.These new and improved minimally invasive surgeries are more precise,specific and effective in treating different types of EGC.

Study on the impact of comprehensive geriatric assessment on anxiety and depression in chronic obstructive pulmonary disease patients

BACKGROUND Psychological factors such as anxiety and depression will not only aggravate the symptoms of chronic obstructive pulmonary disease(COPD)patients and reduce the quality of life of patients,but also affect the treatment effect and long-term prognosis.Therefore,it is of great significance to explore the clinical application of senile comprehensive assessment in the treatment of COPD and its influence on psychological factors such as anxiety and depression.AIM To explore the clinical application of comprehensive geriatric assessment in COPD care and its impact on anxiety and depression in elderly patents.METHODS In this retrospective study,60 patients with COPD who were hospitalized in our hospital from 2019 to 2020 were randomly divided into two groups with 30 patients in each group.The control group was given routine nursing,and the observation group was given comprehensive assessment.Clinical symptoms,quality of life[COPD assessment test(CAT)score],anxiety and depression Hamilton Anxiety Rating Scale(HAMA)and Hamilton Depression Rating Scale(HAMD)were compared between the two groups.RESULTS CAT scores in the observation group decreased from an average of 24.5 points at admission to an average of 18.3 points at discharge,and in the control group from an average of 24.7 points at admission to an average of 18.3 points at discharge.The average score was 22.1(P<0.05).In the observation group,HAMA scores decreased from 14.2 points at admission to 8.6 points at discharge,and HAMD scores decreased from 13.8 points at admission to 7.4 points at discharge.The mean HAMD scores in the control group decreased from an average of 14.5 at admission to an average of 12.3 at discharge,and from an average of 14.1 at admission to an average of 11.8 at discharge.CONCLUSION The application of comprehensive geriatric assessment in COPD care has a significant effect on improving patients'clinical symptoms and quality of life,and can effectively reduce patients'anxiety and depression.

食管癌脑转移的危险因素及生存分析

目的分析食管癌脑转移的危险因素及生存状况。方法回顾性分析2005年1月—2019年1月西安交通大学第二附属医院收治的2 563例食管癌患者的临床资料。使用单因素分析脑转移组与非脑转移组患者的临床病理特征,并进行多因素Logistic回归分析,通过Kaplan-Meyer生存曲线和Log-rankχ2检验比较组间生存时间的差异。结果 2 563例食管癌患者中,脑转移48例(1.87%)。脑转移与非脑转移组的年龄、病理类型、T分期、N分期、颅外转移发生率、伴肺转移发生率、伴肝转移发生率比较,差异均有统计学意义(P <0.05)。多因素分析结果显示,T4期、N2期和N3期、伴肺转移是食管癌脑转移的独立危险因素(P <0.05);脑转移组1年生存率为18.64%,低于非脑转移组的86.93%(P <0.05);单因素和多因素分析结果显示,脑转移数目≥3个、原发灶控制不稳定是影响食管癌脑转移患者生存时间的独立危险因素(P <0.05),其中手术综合治疗是保护性因素(P <0.05)。结论 T4期、N2期和N3期、伴肺转移的食管癌患者更容易发生脑转移,生存状况较差,手术综合治疗在增加生存获益上具有优势。

Economic burden of irritable bowel syndrome in China

AIM To estimate annual direct and indirect costs for patients diagnosed with irritable bowel syndrome(IBS) and subtypes.METHODS Patients completed a standardized questionnaire concerning usage of healthcare resources, travel costs, meals, and productivity loss of patients when seeking treatment for IBS. Total annual costs per patient were calculated as the sum of direct(including medical and nonmedical) and indirect costs. Total annual costs per patient among various IBS subtypes were compared. Analysis of variance and bootstrapped independent sample t-tests were performed to determine differences between groups after controlling for IBS subtypes.RESULTS A total of 105 IBS patients(64.80% female), mean age of 57.12 years ± 10.31 years), mean disease duration of 4.31 years ± 5.40 years, were included. Total annual costs per patient were estimated as CNy18262.84(USD2933.08). Inpatient and outpatient healthcare use were major cost drivers, accounting for 46.41%and 23.36% of total annual costs, respectively. Productivity loss accounted for 25.32% of total annual costs. The proportions of direct and indirect costs were similarto published studies in other countries. Nationally, the total costs of managing IBS would amount to CNy123.83 billion(USD1.99 billion). Among the IBS subtypes, total annual costs per patient of IBS-M was highest at CNy18891.18(USD3034). Furthermore, there was significant difference in productivity loss among IBS subtypes(P = 0.031).CONCLUSION IBS imposes a huge economic burden on patients and healthcare systems, which could account for 3.3% of the total healthcare budget for the entire Chinese nation. More than two-thirds of total annual costs of IBS consist of inpatient and outpatient healthcare use. Among the subtypes, IBS-M patients appear to have the greatest economic burden but require further confirmation.

Small sphincterotomy combined with endoscopic papillary large balloon dilation vs sphincterotomy alone for removal of common bile duct stones

AIM: To evaluate the efficacy and safety of endoscopic papillary large diameter balloon dilation (EPLBD) following limited endoscopic sphincterotomy (EST) and EST alone for removal of large common bile duct (CBD) stones.

Treatment of irritable bowel syndrome in China:A review

Irritable bowel syndrome(IBS)is a common,chronic,functional gastrointestinal disorder with a high incidence rate in the general population,and it is common among the Chinese population.The pathophysiology,etiology and pathogenesis of IBS are poorly understood,with no evidence of inflammatory,anatomic,metabolic,or neoplastic factors to explain the symptoms.Treatment approaches are mainly focused on symptommanagement to maintain everyday functioning and to improve quality of life for patients with IBS.However,prescribed medications often result in significant side effects,and many IBS sufferers(particularly Chinese)do not improve.Instead of taking a variety of conventional medications,many have turned to taking traditional Chinese medicine or integrated Chinese and Western medicine for remedy.A number of clinical trials have shown that Chinese herbal,acupuncture or integrative therapies presented improved treatment outcomes and reduced side effects in IBS patients.The purpose of this review article is to examine the treatment approaches of IBS that have been published in recent years,especially in China,to assess the possible differences in treating IBS between China and other countries.This would provide some useful information of unique treatment approach in clinical practice for physicians in the management of IBS in China,thus offering more treatment options for IBS patients with potentially better treatment outcomes while reducing the medical cost burden.

3D direct writing and micro detonation of CL-20 based explosive ink containing O/W emulsion binder

The booming development of DIW technology present an unprecedented prospect in energetic materials field and has attracted great interest due to its relative simplicity and high flexibility of manufacturing.Herein,a novel CL-20 based explosive ink formulation have been developed successfully for MEMS initiation systems via DIW technology.We designed PVA/GAP into an oil-in-water(O/W)emulsion,in the way that the aqueous solution of PVA as water phase,the ethyl acetate solution of GAP as oil phase,the combination of Tween 80 and SDS as emulsifier,BPS as a curing agent of GAP.The ideal formulation with good shear-thinning rheology properties and clear gel point was prepared using only 10 wt%emulsion.The dual-cured network formed during the curing process made the printed sample have good mechanical properties.The printed samples had satisfactory molding effect without cracks or fractures,the crystal form of CL-20 not changed and the thermal stability have improved.Deposition of explosive inks via DIW in micro-scale grooves had excellent detonation performances,which critical detonation size was 1×0.045 mm,detonation velocity was 7129 m/s and when the corner reaching 150°can still detonated stably.This study may open new avenues for developing binder systems in explosive ink formulations.

Performances and direct writing of CL-20 based ultraviolet curing explosive ink

A new type of explosive ink formulation that can be quickly cured was prepared with unsaturated polyester as binder,styrene as active monomer,2,4,6-trimethylbenzoyl-diphenylphosphine oxide as photoinitiator,and hexanitrohexaazaisowurtzitane(CL-20)as the main explosive.Then the explosive inkdirect writing technology was used to charge the micro-sized energetic devices,the curing mechanism of the explosive ink was discussed,and the microstructure,safety performance and explosive transfer performance of the explosive ink molded samples were tested and analyzed.Results indicate that the composite material has a fast curing molding speed,its hardness can reach 2H within 8 min.The crystal form of CL-20 in the molded sample is still type.The CL-20 based UV-curing explosive ink formulation has good compatibility,its apparent activation energy is increased by about 3.5 kj/mol.The composite presents a significant reduction in impact sensitivity and its characteristic drop height can reach 39.8 cm,whichis about 3 times higher than the raw material.When the line width of charge is 1.0 mm,the critical thickness of the explosion can reach 0.015 mm,and the explosion velocity is 7129 m/s when the charge density is 1.612 g/cm^(3).

2型糖尿病视网膜动脉硬化与心脑血管系统疾病的关系

目的:探讨2型糖尿病视网膜动脉硬化情况及其与心脑血管系统疾病的关系。方法:选取2016-01/2017-01我院收治的2型糖尿病患者85例为研究对象,对患者进行眼底检查,确定其眼底动脉硬化分级情况,并对患者血糖水平进行检测,测定其糖化血红蛋白、空腹血糖和餐后2h血糖水平。患者均随访至少1. 5a,统计随访期间患者心脑血管系统疾病的发生率。比较不同眼底动脉硬化分级患者的血糖水平和心脑血管系统疾病发生率,并分析眼底动脉硬化分级与血糖水平和心脑血管系统疾病的关系。结果:患者85例中,眼底动脉硬化分级为Ⅰ级、Ⅱ级和Ⅲ级患者比例分别为15%(13/85)、52%(44/85)和33%(28/85),随访期间心脑血管系统疾病发生率为27%(23/85)。随着眼底动脉硬化分级的升高,其糖化血红蛋白、空腹血糖、餐后2h血糖水平和心脑血管系统疾病发生率亦升高,差异有统计学意义(P<0. 05)。Spearman相关分析结果显示,2型糖尿病患者眼底动脉硬化分级与其糖化血红蛋白、空腹血糖、餐后2h血糖水平和心脑血管系统疾病发生率均呈正相关(rs=0. 875、0. 792、0. 835、0. 878,P<0. 05)。结论:2型糖尿病眼底动脉硬化严重,且与其血糖水平和心脑血管系统疾病密切相关。

Neuroprotective effects of long noncoding RNAs involved in ischemic postconditioning after ischemic stroke

During acute reperfusion,the expression profiles of long noncoding RNAs in adult rats with focal cerebral ischemia undergo broad changes.However,whether long noncoding RNAs are involved in neuroprotective effects following focal ischemic stroke in rats remains unclear.In this study,RNA isolation and library preparation was performed for long noncoding RNA sequencing,followed by determining the coding potential of identified long noncoding RNAs and target gene prediction.Differential expression analysis,long noncoding RNA functional enrichment analysis,and co-expression network analysis were performed comparing ischemic rats with and without ischemic postconditioning rats.Rats were subjected to ischemic postconditioning via the brief and repeated occlusion of the middle cerebral artery or femoral artery.Quantitative real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of differentially expressed long noncoding RNAs after ischemic postconditioning in a rat model of ischemic stroke.The results showed that ischemic postconditioning greatly affected the expression profile of long noncoding RNAs and mRNAs in the brains of rats that underwent ischemic stroke.The predicted target genes of some of the identified long noncoding RNAs(cis targets)were related to the cellular response to ischemia and stress,cytokine signal transduction,inflammation,and apoptosis signal transduction pathways.In addition,15 significantly differentially expressed long noncoding RNAs were identified in the brains of rats subjected to ischemic postconditioning.Nine candidate long noncoding RNAs that may be related to ischemic postconditioning were identified by a long noncoding RNA expression profile and long noncoding RNA-mRNA co-expression network analysis.Expression levels were verified by quantitative real-time reverse transcription-polymerase chain reaction.These results suggested that the identified long noncoding RNAs may be involved in the neuroprotective effects associated with ischemic postconditioning following ischemic stroke.The experimental animal procedures were approved by the Animal Experiment Ethics Committee of Kunming Medical University(approval No.KMMU2018018)in January 2018.

Microstructure evolution of Ti5Si3 in Cu-Ti-Si alloys

The Cu-Ti-Si alloys containing in-situ formed Ti5Si3 are prepared. In order to clarify the Ti5Si3 formation processes and its microstructure characteristics, the as-cast and deeply etched Cu-Ti-Si alloys with different compositions and cooling rates were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It is found that the eutectic Ti5Si3 phases in Cu-Ti-Si alloys are rod-like with hexagonal cross section which tend to intertwine with each other to form a firm skeleton like a bird nest structure which can make the alloys keep their original shape even after etching off the Cu matrix. In addition, there is Cu in the center of many Ti5Si3 rods, resulting in a core-shell structure. With the increase of the cooling rate, Ti5Si3 distributes more uniformly, and the diameter of Ti5Si3 significantly decreases, with a minimum size of less than 100 nm, while the aspect ratio of Ti5Si3 increases.

硫化氢对糖尿病性白内障大鼠氧化应激的作用及其机制研究

目的:探讨硫化氢(H_2S)对糖尿病性白内障大鼠氧化应激的作用及其作用机制是否涉及调控沉默信息调节因子1(SIRT1)。方法:将SD大鼠随机分为正常对照组、糖尿病模型组、低浓度NaH S组、高浓度NaH S组、单用NaH S组。NaH S作为H_2S 的供体。糖尿病模型组、低浓度NaH S组、高浓度NaH S组大鼠一次性腹腔注射链脲佐菌素(streptozotocin,STZ,65mg/kg)建立糖尿病大鼠模型。采用BQ900裂隙灯观察各组大鼠晶状体的变化。自实验开始12wk后,采用硫代巴比妥酸法检测MDA的含量,黄嘌呤氧化酶法检测SOD的含量,二硫代二硝基苯甲酸法检测GSH-Px的含量; Western blotting检测大鼠晶状体SIRT1的表达。结果:糖尿病组大鼠晶状体出现不同级别的混浊,表明糖尿病性白内障大鼠模型复制成功。分别予低浓度NaH S、高浓度NaH S治疗后糖尿病大鼠晶状体混浊程度得到明显改善。与糖尿病模型组相比,分别给予低浓度NaH S、高浓度NaH S治疗的糖尿病大鼠晶状体MDA的含量明显下降,SOD和GSH-Px的水平显著增加。此外,Western blotting结果显示糖尿病模型组大鼠晶状体SIRT1的表达明显下调,分别予低浓度NaH S、高浓度NaH S治疗能有效逆转该趋势。结论:H_2S能够抑制糖尿病性白内障大鼠氧化应激水平,其机制可能涉及上调SIRT1的表达。

Experimental Point-to-Multipoint Plug-and-Play Measurement-Device-Independent Quantum Key Distribution Network

Measurement-device-independent quantum key distribution(MDI-QKD) offers a practical way to realize a startype quantum network. Previous experiments on MDI-QKD networks can only support the point-to-point communication. We experimentally demonstrate a plug-and-play MDI-QKD network which can support the pointto-multipoint communication among three users. Benefiting from the plug-and-play MDI-QKD architecture,the whole network is automatically stabilized in spectrum, polarization, arrival time, and phase reference. The users only need the encoding devices, which means that the hardware requirements are greatly reduced. Our experiment shows that it is feasible to establish a point-to-multipoint MDI-QKD network.

Fabrication and characterization of mussel-inspired layer-by-layer assembled CL-20-based energetic films via micro-jet printing

Three-dimensional(3D)micro-jet printing is a droplet deposition technique based on liquid-phase materials.To improve the deposition density and performance of energetic films with micro/nanoscale on an energetic chip,polydopamine(PDA)was utilized as a linker bridge to induce the in-situ self-assembly of CL-20-based energetic film via 3D micro-jet printing.The self-assembly was extensively characterized by confocal laser scanning microscopy(CLSM),SEM,power-XRD,XPS,and DSC.The performance of the self-assembled film was verified by the mechanical properties and detonation properties,and a possible self-assembly mechanism in the layer-by-layer micro-jet printing process was proposed.The results indicated PDA-induced self-assembly enhanced the physical entanglement between the binders and energetic crystal,reduced the porosity from 15.87%to 11.28%,and improved the elastic modulus and the detonation performance of the CL-20-based energetic film.This work proposes a novel and promising energetic film design and fabrication strategy to enhance the interaction between the energetic composite layers in the micro-jet printing process.

THUBrachy:fast Monte Carlo dose calculation tool accelerated by heterogeneous hardware for high-dose-rate brachytherapy

The Monte Carlo(MC)simulation is regarded as the gold standard for dose calculation in brachytherapy,but it consumes a large amount of computing resources.The development of heterogeneous computing makes it possible to substantially accelerate calculations with hardware accelerators.Accordingly,this study develops a fast MC tool,called THUBrachy,which can be accelerated by several types of hardware accelerators.THUBrachy can simulate photons with energy less than 3 MeV and considers all photon interactions in the energy range.It was benchmarked against the American Association of Physicists in Medicine Task Group No.43 Report using a water phantom and validated with Geant4 using a clinical case.A performance test was conducted using the clinical case,showing that a multicore central processing unit,Intel Xeon Phi,and graphics processing unit(GPU)can efficiently accelerate the simulation.GPU-accelerated THUBrachy is the fastest version,which is 200 times faster than the serial version and approximately 500 times faster than Geant4.The proposed tool shows great potential for fast and accurate dose calculations in clinical applications.

MANAGEMENT OF URETERAL ENDOMETRIOSIS: A REPORT OF TEN CASES

Objective To investigate the clinical features and management of ureteral endometriosis. Methods Patients surgically and histologically diagnosed as ureteral endometriosis from January 2001 to January 2007 in Peking Union Medical College Hospital were retrospectively reviewed. Results Ten patients were diagnosed as ureteral endometriosis among 7 561 cases with surgically and histologically proved diagnosis of endometriosis, with an incidence of 0.132%. Nine out of 10 patients were extrinsic ureteral endometriosis and concomitant with severe pelvic endometriosis, and the other was intrinsic ureteral endometriosis. Hormone therapy failed in 2 patients with urinary tract obstruction. Ureterolysis was performed in 6 patients and ureterectomy was performed in 4 patients. One case of ureteral recurrence was observed in a postmenopausal woman without hormonal replacement therapy who received laparoscopic ureterolysis and hysterectomy with bilateral adnexectomy. No relapse was observed in the other 9 patients. Conclusions Ureteral endometriosis is a rare entity. The upper urinary tract should be evaluated in patients with severe endometriosis, even in postmenopausal women. The treatment of ureteral endometriosis usually requires surgery, while ureterolysis should not be performed in patients with extensive disease. As a form of adjuvant therapy of surgery, hormonal therapy is an appropriate option.

氮掺杂多孔碳包覆铁纳米粒子催化剂用于高效碱性介质中氧还原反应

合理设计和合成非贵金属催化剂对提高氧还原反应的催化活性和稳定性具有重要意义,但仍然存在重大挑战。本工作采用功能化金属有机框架材料为前驱体,合成了氮掺杂多孔碳包覆Fe纳米粒子催化剂(Fe@N-C)。Fe纳米颗粒的嵌入提高了催化剂的石墨化程度和石墨化氮的比例,同时促进了中孔的形成。Fe@N-C-30催化剂在碱性溶液中表现出良好的氧还原反应活性(E_(0)=0.97V vs.RHE,E1/2=0.89V vs.RHE)。此外,与商用Pt/C相比,Fe@N-C-30催化剂具有更好的耐甲醇性和循环稳定性。其优异的电催化活性归因于高的电化学表面积、相对高比例的石墨化氮、独特的孔结构以及包覆的Fe颗粒与碳层之间的协同效应。本工作为利用金属有机框架材料制备高效非贵金属ORR催化剂提供了一种有前景的方法。

Resonance-Enhanced Photon Excitation Spectroscopy of the Even-Parity Autoionizing Rydberg States of Xe

Xenon atoms were produced in their metastable states 5p^56s[3/2]2 and 5p^56s＇[1/2]0 in a pulsed DC discharge in a beam, and subsequently excited to the even-parity autoionizing Rydberg states 5p^5np＇ [3/2] 1,[1/2] 1, and 5p^5nf＇ [5/2] 3 using single photon excitation. The excitation spectra of the even-parity autoionizing resonance series from the metastable 129Xe were obtained by recording the autoionized Xe＋ with time-of-flight ion detection in the photon energy range of 28000-42000 cm-1. A wealth of autoionizing resonances were newly observed, from which more precise and systematic spectroscopic data of the level energies and quantum defects were derived.