Hard Spot Research Articles

A fast and robust constraint-based online re-optimization approach for automated online adaptive intensity modulated proton therapy in head and neck cancer

Objective. In head-and-neck cancer intensity modulated proton therapy, adaptive radiotherapy is currently restricted to offline re-planning, mitigating the effect of slow changes in patient anatomies. Daily online adaptations can potentially improve dosimetry. Here, a new, fully automated online re-optimization strategy is presented. In a retrospective study, this online re-optimization approach was compared to our trigger-based offline re-planning (offlineTB re-planning) schedule, including extensive robustness analyses. Approach. The online re-optimization method employs automated multi-criterial re-optimization, using robust optimization with 1 mm setup-robustness settings (in contrast to 3 mm for offlineTB re-planning). Hard planning constraints and spot addition are used to enforce adequate target coverage, avoid prohibitively large maximum doses and minimize organ-at-risk doses. For 67 repeat-CTs from 15 patients, fraction doses of the two strategies were compared for the CTVs and organs-at-risk. Per repeat-CT, 10.000 fractions with different setup and range robustness settings were simulated using polynomial chaos expansion for fast and accurate dose calculations. Main results. For 14/67 repeat-CTs, offlineTB re-planning resulted in <50% probability of D 98% ≥ 95% of the prescribed dose (D pres) in one or both CTVs, which never happened with online re-optimization. With offlineTB re-planning, eight repeat-CTs had zero probability of obtaining D 98% ≥ 95%D pres for CTV7000, while the minimum probability with online re-optimization was 81%. Risks of xerostomia and dysphagia grade ≥ II were reduced by 3.5 ± 1.7 and 3.9 ± 2.8 percentage point [mean ± SD] (p < 10−5 for both). In online re-optimization, adjustment of spot configuration followed by spot-intensity re-optimization took 3.4 min on average. Significance. The fast online re-optimization strategy always prevented substantial losses of target coverage caused by day-to-day anatomical variations, as opposed to the clinical trigger-based offline re-planning schedule. On top of this, online re-optimization could be performed with smaller setup robustness settings, contributing to improved organs-at-risk sparing.

Molecular identification of Borrelia and SFG Rickettsia spp. in hard ticks parasitizing domestic and wild animals in southeastern Spain

Lyme disease and the spotted fever group rickettsiosis, involve bacteria belonging to the genus Borrelia and Rickettsia, respectively. These infections are the most important tick-borne zoonotic diseases involving ticks as vectors. Descriptive and epidemiological studies are essential to determine the animal hosts involved in the maintenance of these diseases. In the present study, 94 tick pool samples from 15 different host species located in the Region of Murcia (southeastern, Spain) were analysed. Ticks were morphologically identified as: Dermacentor marginatus, Hyalomma lusitanicum, Ixodes Ricinus, and Rhipicephalus sanguineus. Our results showed that 5.3% of the tick pool samples carried Borrelia spp. DNA, and 20.2% carried SFG Rickettsia DNA. In every hard tick pool Spot Fever Group (SFG) Rickettsia spp. DNA were detected, except for H. lusitanicum. Likewise, D. marginatum was the only species in which Borrelia spp. DNA was not detected. Barbary sheep and wild boar were the host species in which tick pools showed DNA presence of both pathogens. This study increases the knowledge about the presence of Borrelia spp. DNA and SFG Rickettsia spp. DNA in different hard tick species from this geographical area.

Active Optics and Aberration Correction Technology for Sparse Aperture Segmented Mirrors

Active optics and aberration correction techniques for sparse aperture segmented mirrors are studied. A finite element model of the sparse aperture segmented mirror was established, and a multi-aperture aberration polynomial was derived. According to the hard spot theorem, a co-phase maintenance method based on the change of the edge sensor position in the conventional mode is derived. And a co-phase maintenance method based on the change of the aberration of the segmented mirror surface without the participation of the edge sensor is proposed. The method can correct aberrations of the segmented mirror surface, which are caused by the rigid body displacement along the horizontal direction of the segments. This method can reduce the RMS of the segmented mirror surface to 2.2 nm. The correction principle of the Warping Harness (WH) technique is derived. For the problems of tedious steps and a small number of target aberrations, the correction method is proposed to directly target the aberrations of the segmented mirrors, which is simple and has a wider range of target aberrations. Using this method, the amplitude of each aberration of the stitched mirror is corrected to below 10−4nm. It is also verified that combining the generalized ridge estimation method and the differential evolution algorithm can effectively solve the correction quantity. Finally, it is verified that the SiC material can effectively improve the adaptability of the segmented mirror to gravity load by reducing the mirror’s weight.

RF14 | PMON320 Ovarian Malignancy, Familial Multinodular Goiter Associated with DICER1 Mutation

Abstract Background DICER1 syndrome, a rare autosomal dominant disorder, places affected individuals at risk for benign and malignant tumors of multiple organs, including thyroid, ovaries, lungs, kidneys, CNS. These tumors occur in childhood and usually before 40 years of age. Clinical Case A 15-year old female presented with worsening abdominal pain and vomiting. She noted a "hard spot" on her abdomen and reported secondary amenorrhea with worsening acne and development of hirsutism over the previous 12 months. Imaging evaluation showed a 9 cm×19 cm×13 cm right ovarian mass with no enlarged lymph nodes. Initially, tumor markers and hormone levels were elevated: Alpha Fetoprotein 424 ng/mL [0-7], Testosterone 208 ng/dL [12-60], Free Testosterone 6.03 ng/dL [0.04-1.09], Inhibin A 129 pg/mL [97.5], Inhibin B 817 pg/mL [&amp;lt; 136], LDH 742 unit/L [370-645]. Patient underwent right salpingo-oophorectomy, lymph node and omentum biopsy; pathologic exam showed Stage 1C Sertoli-Leydig tumor of the right ovary (intermediate to poorly differentiated). She received chemotherapy with Cisplatin, Etoposide, Bleomycin. Genetic analysis revealed that she is heterozygous for a likely pathogenic variant, c.343del (p.Thr115Leufs*13) in DICER1, consistent with a diagnosis of autosomal dominant DICER1-associated disease. After therapy ended, her tumor markers and hormone levels normalized. Patient was found to have a multinodular goiter with benign pathology; her thyroid function remained normal. A 2 mm right middle lobe pulmonary nodule, stable, has been present on chest CT. Family history is significant for an euthyroid multinodular goiter with benign nodules in her 2-year older brother who has the same DICER1 pathogenic variant. Their mother and maternal grandmother also had total thyroidectomy for multinodular goiter. Conclusion A cluster of certain tumors in family members involving successive generations, should prompt evaluation for a genetic cause, as early diagnosis, management and appropriate surveillance improve patients’ quality of life. Presentation: Sunday, June 12, 2022 12:54 p.m. - 12:59 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Detection of citrus black spot symptoms using spectral reflectance

Citrus black spot (CBS) disease can usually result in fruit blemish and yield loss on all citrus. Spectral reflectance was utilized to detect CBS symptoms in this study. Hyperspectral images of both healthy and diseased citrus were collected in the spectral region of 396−1010 nm. After raw image calibration, spectral reflectance of diseased (early hard spot, advanced hard spot, cracked spot, early virulent, and virulent) and healthy samples were extracted and used as independent variables for classification. Effective wavelengths were selected using regression coefficients based on partial least squares analysis. K-nearest neighbor models were established to classify the symptoms in each group (early hard spot vs. advanced hard spot, early virulent vs. virulent, hard spot vs. cracked spot, hard spot vs. virulent, cracked spot vs. virulent, diseased vs. healthy, and early stage vs. advanced stage). In diseased vs. healthy group, the models yielded the correct classification accuracies of 99.4 % (using full wavelengths) and 100.0 % (using selected wavelengths) for diseased samples. The correct classification accuracies were 92.5 % (using full wavelengths) and 93.8 % (using selected wavelengths) for early stage samples (early disease). Besides, the selected wavelengths were 549, 668, 706, and 790 nm for diseased vs. healthy group, and 675, 711, and 835 nm for early stage vs. advanced stage group. The overall results demonstrated that spectral reflectance information has the potential to classify different symptoms of CBS.

Development of steady arm damper for electrified railway overhead contact line with double pantographs based on numerical and experimental analysis

To improve the carrying capacity, double pantographs are normally used to collect the electric current from the catenary. The mechanical wave excited by the leading pantograph affects the contact of the trailing pantograph and the contact wire, which usually deteriorates the current collection quality. To address this issue, a steady arm damper is developed in this work to reduce the wave intensity caused by the leading pantograph. The catenary is modelled by Absolute Nodal Coordinate Formulation. The numerical simulations indicate that the steady arm damper with certain values reduces the contact force variation of the trailing pantograph. But overlarge damping may behave as a hard spot and aggravates the interaction performance. The acceptable steady arm damping should be lower than 300 Ns/m. The optimal value of the steady arm damping coefficient varies with the train speed. The realistic damping ratio should be determined based on the operating speed of a railway line. Based on the simulation results, several realistic steady arm dampers are developed, which are placed between the cantilever and the end of the steady arm. An experimental test is conducted to investigate the effect of the steady arm damper on the reduction of vibration caused by the dropping sinker. The experimental results demonstrate that the steady arm damper can reduce the mechanical wave amplitude and eliminate its effect on the trailing pantograph.

Hydrogen assisted cracking driven by cathodic protection operated at near −1200 mV CSE – an onshore natural gas pipeline failure

A 22-inch onshore natural gas transmission pipeline in operation since 1960 experienced an in-service rupture in January of 2018. The rupture was caused by an axial crack located 150 km (93 miles) downstream of the closest compression station. While the root cause analysis of the rupture was being carried out, excavations of indications reported by a Hard Spot In-Line Inspection approximately 42 km (26 miles) downstream of the rupture found leaks from predominantly circumferential crack colonies mixed with spiderweb ones not associated with hard spots.The conclusion from this investigation is that the cracking mechanism for the in-service rupture and leaks is mainly hydrogen environment assisted cracking (HAC), with the hydrogen being generated by the cathodic protection. The root cause for the failures is the combination of an aged and defective coating and the cathodic protection (CP) system operated for decades at near the pipe-to-soil potential limit of −1200 mV CSE.An extensive literature search indicates that this investigation is the first fully documented case of an onshore transmission pipeline failure due to HAC driven by CP, with the cracks occurring in the pipe body of X52 steel, away from welds and not related with hard spots. The paper summarizes the approach used for the root cause analysis and the findings, where the implications in the management of the pipeline integrity of the pipeline system are discussed. The pipeline operator implemented a series of preventive and corrective measures, which included pressure testing, cathodic protection improvement, coating rehabilitation programs and In-Line Inspection programs.

Destabilizing role of futures markets on North American hard red spring wheat spot prices

AbstractThe objective of the paper is to determine if the futures prices of hard red spring wheat (HRSW) have stabilizing or destabilizing impact on spot HRSW price in North America. Several important results emerge from thorough empirical analysis. First, both Granger causality tests and directed acyclic graph algorithms (DAGs) point to two‐way causality between futures and spot HRSW prices and thus endogeneity in both prices formation. To the contrary, both procedures suggest that ending stocks are exogenous to spot and futures HRSW prices. Both vector error correction model and impulse response functions point to a large and long‐lasting impact of a shock to futures price on spot price level. Finally, variance decomposition analysis indicates that futures prices are responsible for the bulk of spot price volatility in both short and long run. Our result is consistent with those of theoretical models suggesting that when production (supply side) is the dominant disturbance, spot price is destabilized in both the short and the long run by futures prices. An important implication of this research is the need for alternative market mechanisms or alternative farm policy measures that would mitigate price risk and ensure sustainable farming of American HRSW farmers.

Seed distribution by the coulter for the subsoil broadcast seeding

The article studies the efficiency of the subsoil broadcast seeding of grain crops, which differs from other methods with the way seeds are placed into the soil: not in rows but on the whole distributing width. This method is also determined by the evenness of seeding depth by placing the seeds on the ready hard spot, which provides equal conditions of heat, light, water, food and gas supply that influence seed sprouting, seedling formation, tillering, shooting, head formation, earing, blossoming, kernel milk line formation, middle dough and fully ripe stage development. The analysis of coulter with active and passive distributors has been conducted. The use of air flow during the transportation of seeds from the sowing device to the coulter and the distributor oscillating process is recommended for the higher quality seed distribution below the spinning wheel. The oscillations of the elastic tube – distributor under the influence of the air-grain mixture have been theoretically studied. The obtained results allow creating dependency diagrams of oscillation frequency ω and damping parameter h. The experimental research has been made to study the evenness of seed distribution with the help of the coulter with the elastic tube – distributor.

The Effect of Weather and Location of Fruit within the Tree on the Incidence and Severity of Citrus Black Spot on Fruit

Citrus black spot (CBS) caused by the fungus Phyllosticta citricarpa occurs in tropical and sub-tropical citrus production regions and affects all varieties of citrus. In Florida, the disease cycle is unique, having only the asexual spore. This work examines incidence and severity of CBS (hard spot symptoms) on fruit in two citrus groves during 2013–2014, 2014–2015 (Grove III) and 2015–2016 (Grove II) citrus seasons. Disease incidence and severity on fruit were analyzed based on citrus season, side of tree evaluated, height within the canopy, tree health, and tree age. Results indicate an increase in CBS incidence in Grove III between 2013–2014 and 2014–2015 seasons, with more infected or symptomatic fruit on the road side of the canopy and a higher incidence above 2 meters. Tree health status affected incidence but not severity and tree age had a significant effect on severity of CBS in Grove II. Analysis of weather data conducive for infection, between 2010 and 2017, indicated an average of 172 days per year (range: 104–261 days) when the temperature (15–35 °C) and relative humidity (RH ≥ 90% for 8 consecutive hours) were conducive for infection of fruit and an average of 98 days per year (range: 72–123 days) when the fruit were susceptible to infection.

Phyllosticta citricarpa and sister species of global importance to Citrus.

SummarySeveral Phyllosticta species are known as pathogens of Citrus spp., and are responsible for various disease symptoms including leaf and fruit spots. One of the most important species is P. citricarpa, which causes a foliar and fruit disease called citrus black spot. The Phyllosticta species occurring on citrus can most effectively be distinguished from P. citricarpa by means of multilocus DNA sequence data. Recent studies also demonstrated P. citricarpa to be heterothallic, and reported successful mating in the laboratory. Since the domestication of citrus, different clones of P. citricarpa have escaped Asia to other continents via trade routes, with obvious disease management consequences. This pathogen profile represents a comprehensive literature review of this pathogen and allied taxa associated with citrus, focusing on identification, distribution, genomics, epidemiology and disease management. This review also considers the knowledge emerging from seven genomes of Phyllosticta spp., demonstrating unknown aspects of these species, including their mating behaviour.Taxonomy Phyllosticta citricarpa (McAlpine) Aa, 1973. Kingdom Fungi, Phylum Ascomycota, Class Dothideomycetes, Order Botryosphaeriales, Family Phyllostictaceae, Genus Phyllosticta, Species citricarpa.Host rangeConfirmed on more than 12 Citrus species, Phyllosticta citricarpa has only been found on plant species in the Rutaceae.Disease symptoms P. citricarpa causes diverse symptoms such as hard spot, virulent spot, false melanose and freckle spot on fruit, and necrotic lesions on leaves and twigs.Useful websitesDOE Joint Genome Institute MycoCosm portals for the Phyllosticta capitalensis (https://genome.jgi.doe.gov/Phycap1), P. citriasiana (https://genome.jgi.doe.gov/Phycit1), P. citribraziliensis (https://genome.jgi.doe.gov/Phcit1), P. citrichinaensis (https://genome.jgi.doe.gov/Phcitr1), P. citricarpa (https://genome.jgi.doe.gov/Phycitr1, https://genome.jgi.doe.gov/Phycpc1), P. paracitricarpa (https://genome.jgi.doe.gov/Phy27169) genomes.All available Phyllosticta genomes on MycoCosm can be viewed at https://genome.jgi.doe.gov/Phyllosticta.

Sweet Orange Fruit Age and Inoculum Concentration Affect the Expression of Citrus Black Spot Symptoms.

Citrus black spot (CBS), caused by Phyllosticta citricarpa, affects different citrus species worldwide. CBS is mainly expressed as false melanose and hard spot symptoms. There is no consensus in the literature about the period when fruit are susceptible to P. citricarpa infection and the length of the CBS incubation period. Therefore, this study aimed to assess the influence of sweet orange variety, fruit age, and inoculum concentration on the incubation period and the expression of different CBS symptoms. Attached fruit of Hamlin, Pera, and Valencia sweet orange at 1.5, 3.0, 5.0, and 7.0 cm diameter were inoculated with suspensions containing 103 and 105 conidia/ml of P. citricarpa. The percent conidial germination was quantified using scanning electron microscopy. The CBS symptoms on fruit were assessed monthly. The four diameters did not significantly affect conidial germination on the inoculated fruit, although CBS incidences were lower when larger fruit were inoculated. Hard spot symptoms on sweet orange fruit did not develop from the false melanose symptoms and vice versa. The incubation periods for false melanose were shorter than those observed for hard spot. False melanose began to appear 44 days after inoculation, but hard spot only formed at 113 days or later. Incubation periods were shorter and incidences of false melanose were higher following inoculation with higher inoculum concentration and smaller fruit diameter. The incubation period of hard spot varied among varieties and fruit diameters. However, there was no relationship between hard spot incidence and variety. This study provides a better understanding of the factors affecting the variation in the CBS incubation period and disease incidence on fruit.

First Report of Phyllosticta citricarpa Causing Citrus Black Spot on Citrus sinensis and C. reticulata in India

Citrus is an economically important fruit crop in India. In December 2016, citrus black spot (CBS)-like symptoms were observed on Nagpur mandarin (Citrus reticulata), ‘Mosambi’ sweet orange, and Cutter Valencia (C. sinensis) trees in two orchards situated at Mohpa and Kachimet localities of Nagpur district, Maharashtra state (21.14 to 21.30°N, 78.82 to 79.02°E). Later symptoms were also noticed on Nagpur mandarin and Mosambi fruits in the fresh fruit market of Nagpur (also known as “Orange City”). Fruit symptoms included hard spot, red-brown spot, freckle spot, and virulent spot. To isolate the causal agent, fruit lesions were surface disinfested with 1% NaOCl and plated on potato dextrose agar (PDA) and oatmeal agar (OA). Fifteen single-spore cultures resembling those of the genus Phyllosticta were obtained. On PDA, the colonies had irregular margins, with numerous pycnidia, lined by a translucent zone of colorless submerged mycelium. On OA, a distinct yellow pigment was produced that diffused into the medium around the colony. Conidia (9.6 to 10.3 × 5.9 to 9.0 μm; average, 9.9 × 7.3 μm; n = 30) were hyaline, aseptate, ovoid with a flattened base surrounded by a hyaline matrix (0.8 to 1.1 μm; average, 0.9 μm; n = 30) and a hyaline appendage (6.6 to 13.6 μm; average, 8.8 μm; n = 30) on the rounded apex, corresponding to published descriptions of P. citricarpa (sexual morph Guignardia citricarpa) (Baayen et al. 2002). Leptodothiorella spermatial state formed in pure culture, and spermatia (4.8 to 7.9 × 0.8 to 1.3 μm; average, 7.0 × 1.0 μm; n = 30) were hyaline, dumbbell shaped to cylindrical, and both ends bluntly rounded. No sexual structures were observed. DNA was extracted from six representative isolates (CB1 to CB6) using a Qiagen DNeasy Plant Mini Kit. The nuclear ribosomal internal transcribed spacer (ITS) region (GenBank accession nos. MF000337 to MF000341 and MF062501) and the translation elongation factor 1-alpha gene (tef1) (MF000342 to MF000347) were amplified and sequenced using universal primer pairs ITS5/ITS4 and EF1-728F/EF2, respectively. These isolates shared 99 to 100% nucleotide sequence similarity (for both ITS and tef1) among themselves and had 99 to 100% homology with P. citricarpa ITS sequences from the United States (GenBank no. KC311457) and South Africa (KF709953) and with the P. citricarpa tef1 sequence of an Australian isolate (GenBank no. JF343602). The P. citricarpa-specific primers GCN and GCMR (Peres et al. 2007) produced a 300-bp band from the DNA extracts of fruit lesions and pure cultures but not from healthy citrus tissue DNA. To confirm pathogenicity, two isolates (CB1 and CB4) were inoculated into Mosambi sweet orange (six fruits for each isolate), as described by Rodrigues et al. (2013). After 30 days, all the inoculation sites showed early hard spot-like CBS symptoms. Control fruits remained symptomless. P. citricarpa was consistently reisolated from the fruit lesions and identified by morphology and ITS sequencing. Earlier, P. citricarpa was noted on Citrus medica leaves in Chennai, India (Kumaran et al. 2008), but there was no proof of identification and characterization of the species. To our knowledge, this is the first confirmed report of P. citricarpa causing CBS in two economically important Citrus species, C. sinensis and C. reticulata, in India. The disease is of great importance to the Indian citrus industry because it inflicts serious fruit blemishes and can cause severe yield reduction under heavy disease pressure.

Engineering d-limonene synthase down-regulation in orange fruit induces resistance against the fungus Phyllosticta citricarpa through enhanced accumulation of monoterpene alcohols and activation of defence.

Terpene volatiles play an important role in the interactions between specialized pathogens and fruits. Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, is associated with crop losses in different citrus-growing areas worldwide. The pathogen may infect the fruit for 20-24weeks after petal fall, but the typical hard spot symptoms appear when the fruit have almost reached maturity, caused by fungal colonization and the induction of cell lysis around essential oil cavities. d-Limonene represents approximately 95% of the total oil gland content in mature orange fruit. Herein, we investigated whether orange fruit with reduced d-limonene content in peel oil glands via an antisense (AS) approach may affect fruit interaction with P.citricarpa relative to empty vector (EV) controls. AS fruit showed enhanced resistance to the fungus relative to EV fruit. Because of the reduced d-limonene content, an over-accumulation of linalool and other monoterpene alcohols was found in AS relative to EV fruit. A global gene expression analysis at 2h and 8days after inoculation with P.citricarpa revealed the activation of defence responses in AS fruit via the up-regulation of different pathogenesis-related (PR) protein genes, probably as a result of enhanced constitutive accumulation of linalool and other alcohols. When assayed invitro and invivo, monoterpene alcohols at the concentrations present in AS fruit showed strong antifungal activity. We show here that terpene engineering in fruit peels could be a promising method for the development of new strategies to obtain resistance to fruit diseases.

Spectral Characteristics of Citrus Black Spot Disease

Citrus black spot (CBS) is a fungal disease caused by Phyllosticta citricarpa (synonym Guignardia citricarpa). CBS causes fruit lesions and significant yield loss in all citrus (Citrus) species. The most distinguishing CBS symptom is called hard spot, which is a circular lesion with gray tissue at the center surrounded by a black margin. The spectral characteristic of CBS lesions was investigated and compared with the spectral signature of healthy fruit tissue to determine the best distinguishing wave band. Healthy and CBS-affected samples presented similar reflectance below 500 nm and above 900 nm. However, healthy samples reflected more light between 500 and 900 nm, especially within the visible band. Also, spectral reflectance of the same symptomatic lesion was acquired six times over a 2-month period to determine the variation of symptom’s spectral signatures over time after being harvested. A two-sample t test was employed to compare each pair of consecutive repetitions. The results showed that the spectral signature of the CBS lesion did not change significantly over 2 months. The wavelengths between 587 and 589 nm were identified as the distinguishing band to develop a monochrome vision–based sensor for CBS diagnosis. A support vector machine (SVM) classifier was trained using the spectral reflectance data at the selected bands to identify CBS-affected samples in each repetition. The overall CBS detection accuracies varied between 93.3% and 94.6%.

Hard Spots in ADC12 Die Casting Cylinder Block Used for Air Compressor

The hard spots are investigated in ADC12 die casting cylinder blocks for air compressors using metallographic method and a micro- hardness tester. The results show that the hard spots have two main shapes. There is a nonuniform micro-hardness distribution within a hard spot. Energy dispersive spectrometry (EDS) analysis reveals that these hard spots are some kind of mixture of oxide and carbide, which are formed during melting and die casting process.

Study the Properties of Abrasive Stone for Aluminum Grinding

A doubled-sided lapping machine of grinding stone manufactured of a SiC as an abrasive, specific resin and other thermosetting resin were developed for grinding process of the substrate of hard disk drive (HDD) made up of aluminum since the conventional lapping machine cause the serious quality problem of the magnetic substrate. However, at certain parameter during the grinding process, the abrasive stone was clogging due to the agglomeration of debris from the substrate which cause scratches on the magnetic substrates and affect its performance. The samples were classified into four parts (soft spot, border spot, hard spot, and unused spot). Characterizations of the samples were done using XRF, SEM and FTIR analysis. Based on all the above analysis, it can conclude that the porosity of the stone were not homogeneous and the percentage of Al was highest at the border spot which shows that, the area at the border spot cause the clogging to occur thus produces the hard spot that will damage the magnetic substrate during grinding process.

Diagnostic value of high frequency color doppler ultrasound for lower limb artery lesions in patients with diabetes

Objective To explore the clinical value of high frequency color doppler ultrasound in the diagnosis of lower limb artery pathological changes of diabetes.Methods Linear array of high frequency probe was used in regular line double lower limbs artery ultrasound examination in 102 cases with diabetes (observation group) and 98 healthy people(control group).The lower limb artery(including femoral artery,popliteal artery,posterior tibial artery,the tibia and dorsalis pedis artery)before the intima-media thickness (IMT)were measured,and the presence of plaque,the plaque nature,the degree of luminal stenosis or occlusion of the judgment and hemodynamic changes were observed.Results In observation group,the femoral artery plaque detection rate was 22％,popliteal artery plaque detection rate was 36％,posterior tibial artery plaque detection rate was 39％,pretibial artery plaque detection rate was 38％,dorsalis pedis artery plaque detection rate was 45％.In control group,the femoral artery plaque detection rate was 9％,popliteal artery plaque detection rate was 7％,posterior tibial artery plaque detection rate was 10％,pretibial artery plaque detection rate was 13％,dorsalis pedis artery plaque detection rate was 16％.In the observation group,lower limb artery plaque caused mild stenosis in 31 cases,moderate stenosis 16 cases,severe stenosis 11 cases,block 4 cases.In the control group,9 cases had mild stenosis caused by lower limb artery plaque,moderate stenosis 5 cases,3 cases with severe stenosis and occlusion in 0 case.In the observation group,lower limb artery soft spot 14,hard spots in 19,41 mixed plaques.In the control group,lower limb artery soft spot 4,hard spot 8,11 mixed plaques.Conclusion Lower limb artery pathological changes is closely related with diabetes,especially the artery stenosis and block the knee can predict the development of diabetes. Key words: Color doppler ultrasound; Lower extremity arterial; Diabetes

Effects of Different Sodic Deflocculants on Rheological Properties of Acid-Resistant Overglaze Slip

This paper aims at solving the poor rheology of clay-water- acid-resistant overglaze slip. Natronite, tripolyphosphate sodium and composite deflocculant compounded of sodium natronite and sodium tripolyphosphate in proportion of 1:2 respectively were taken as deflocculants, and single-factor test and ring test were used to measure the variations in zeta-potential, viscosity and thixotropic. The results show that 0.3% of the composite deflocculants are better than any other single deflocculants on clay-water-acid-resistant overglaze slip, which has a better liquidity, a better thixotropy and a better stability that can avoid defects on glaze such as crawling, pinhole, hard spot, focal spot. Some factual and theoretic bases can be provided for enamel industry.

In a hard spot: Providing group prenatal care in two urban clinics

In a hard spot: Providing group prenatal care in two urban clinics