PbrARF4 contributes to calyx shedding of fruitlets in ‘Dangshan Suli’ pear by partly regulating the expression of abscission genes

Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (DAFB) higher levels of indoleacetic acid (IAA) and tryptophan (Trp) in calyx persistence fruitlet (CPF) than calyx shedding fruitlet (CSF) ofDanshan Suli’ pear (Pyrus bretschneideri Rhed.). Consisting with this, the activity of indolealdehyde oxidase (IAAIdO), which promotes IAA synthesis, was remarkably increased, and that of peroxidase(POD), which degrades IAA, dropped markedly in CPF but not in CSF. Further, qRT-PCR results revealed that most of 31 PbrARFs (encoding auxin response factors) in Pyrus bretschneideri were highly expressed in CPF, whereas PbrARF4, PbrARF24 and PbrARF26 were significantly downregulated in CPF vis-a-vis CSF. Phylogenetic analysis revealed that 6 PbrARFs clustered in the group III, where PbrARF4 showed the closest affinity with AtARF1 that promotes organ abscission, indicating a putative role of PbrARF4 in mediating the process of calyx shedding in pear. In fact, the ectopic overexpression of PbrARF4 in Solanum lycopersicum resulted in an earlier-formed and deeper abscission layer (AL) in the transgenic plants, whose calyxes were more prone to wilt at the mature red stage (MR) compared with the control plants (wild-type). More importantly, expression levels of the abscission genes SILS and Sl Cel2 in transgenic plants overexpressing PbrARF4 were significantly upregulated in comparation with the WT, whereas those of Sl BI and Sl TAPG2 were considerably inhibited. Further, PbrJOINTLESS and PbrIDA,the two genes related to calyx shedding in pear, were up-regulated more in CSF than CPF. The findings contribute to a better understanding of PbrARFs involved in fruitlet calyx shedding of pear, which could prove beneficial to improving the quality of pear fruit.

Characteristics of Viral Shedding in Respiratory Samples and Specific Antibodies Production in 564 COVID-19 Patients

Positive nucleic acid(NA)results have been found in recovered and discharged COVID-19 patients,but the proportion is unclear.This study was designed to analyze the recurrent positive rate of NA results after consecutively negative results,and the relationship between the specific antibody production and positive NA rate.According to Strengthening the Reporting of Observational Studies in Epidemiology guidelines,data of inpatients in Sino-French New City Branch of Tongji Hospital between Jan.28 and Mar.6,2020 were collected.A total of 564 COVID-19 patients over 14 years old who received the examinations of NA and antibodies against SARS-CoV-2 were included.Days of viral shedding and specific antibodies were recorded and assessed.Among NA tests in respiratory samples(throat swabs,nasopharyngeal swabs,sputum and flushing fluid in alveoli),the patients with all-negative NA results accounted for 17.20%,those with single-positive results for 46.63%,and those with multiple-positive results for 36.17%respectively.Besides,the recurrent positive NA results after consecutively negative results appeared in 66 patients(11.70%).For multiple-positive patients,median viral shedding duration was 20 days(range:1 to 57 days).Of the 205 patients who received 2 or more antibody tests,141(68.78%)had decreased IgG and IgM concentrations.IgM decreased to normal range in 24 patients,with a median of 44 days from symptom onset.Viral shedding duration was not significantly correlated with gender,age,disease severity,changes in pulmonary imaging,and antibody concentration.It is concluded that antibody level and antibody change had no significant correlation with the positive rate of NA tests and the conversion rate after continuous negative NA tests.In order to reduce the recurrent positive proportion after discharge,3 or more consecutive negative NA test results with test interval more than 24 h every time are suggested for the discharge or release from quarantine.

An unusual COVID-19 case with over four months of viral shedding in the presence of low neutralizing antibodies: a case report

The ongoing coronavirus disease 2019(COVID-19)pandemic is a global public health crisis,causing social and economic disasters in many countries.In China,two-consecutive negative results of nucleic acid tests for SARS-CoV-2 from the respiratory samples are required to end the quarantine of COVID-19 patients.However,clinicians face a dilemma in case of patients with long-term viral shedding.This report described an unusual COVID-19 case who had persistent viral RNA positivity for more than 4 months after initial illness in the presence of low neutralizing antibodies,but without prolonged clinical symptoms.Multiple anti-viral drug treatments had no impact and there was no evidence of re-infection.When the patient was self-quarantined at home,no infection occurred to the three family members living with her for 15 to 19 days.Sputum viral culture in BSL-3 laboratory on the 102nd day after symptom onset was negative.From the 129th day on,8 continuous nucleic acid tests of sputum samples showed negative results.The patient was discharged on 137th days since symptom onset.In conclusion,viral RNA shedding in the sputum of the COVID-19 patient may last over 4 months.As no evidence shows the existence of infectious virus,two-consecutive negative nucleic acid tests may not be the prerequisite for ending quarantine of COVID-19 patients with prolonged viral shedding.

Load Profile Analysis for Mitigating Load-Shedding in Central Africa: Case of Kinshasa

Load shedding is a major problem in Central Africa, with negative consequences for both society and the economy. However, load profile analysis can help to alleviate this problem by providing valuable information about consumer demand. This information can be used by power utilities to forecast and reduce power cuts effectively. In this study, the direct method was used to create load profiles for residential feeders in Kinshasa. The results showed that load shedding on weekends results in significant financial losses and changes in people’s behavior. In November 2022 alone, load shedding was responsible for $ 23,4 08,984 and $ 2 80,9 07,808 for all year in losses. The study also found that the SAIDI index for the southern direction of the Kinshasa distribution network was 122.49 hours per feeder, on average. This means that each feeder experienced an average of 5 days of load shedding in November 2022. The SAIFI index was 20 interruptions per feeder, on average, and the CAIDI index was 6 hours, on average, before power was restored. This study also proposes ten strategies for the reduction of load shedding in the Kinshasa and central Africa power distribution network and for the improvement of its reliability, namely: Improved load forecasting, Improvement of the grid infrastructure, Scheduling of load shedding, Demand management programs, Energy efficiency initiatives, Distributed Generation, Automation and Monitoring of the Grid, Education and engagement of the consumer, Policy and regulatory assistance, and Updated load profile analysis.

Therapeutic targeting of cellular prion protein: toward the development of dual mechanism anti-prion compounds

PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.

On the Sub-Critical Bifurcation of Anti-Phase and In-Phase Synchronized Vortex Shedding Forms

Transition of flows past a pair of side-by-side circular cylinders are investigated by numerical simulations and the bifurcation analysis of the numerical results. Various flow patterns behind the cylinder-pair have been identified by the gap ratio (G) and Reynolds number (Re). This study focus on transition of in-phase and anti-phase vortex shedding synchronized forms. A nested Cartesian-grid formulation, in combination with an effective immersed boundary method and a two-step fractional-step procedure, has been adopted to simulate the flows. Numerical results reveal that the in-phase and anti-phase vortex shedding flows at Re = 100 can co-exist at 2.08 ≤G≤ 2.58. Hysteresis loop with increasing/decreasing G at constant Reynolds number Re = 100 is reported.

Effect of perforation on flow past a conic cylinder at Re=100:vortex-shedding pattern and force history

The flow past a circular-section cylinder with a conic shroud perforated with four holes at the peak was simulated numerically at Re = 100, considering two factors, viz.the angle of attack and the diameter of the holes. The effects of the perforated conic shroud on the vortex shedding pattern in the near wake was mainly investigated, as well as the time history of the drag and lift forces. In the investigated parameter space, three flow regimes were generally identified, corresponding to weak, moderate, and strong disturbance effects.In regime I, the wake can mainly be described by alternately shedding Kármán or Kármán-like vortices. In regime II, the spanwise vortices are obviously disturbed along the span due to the appearance of additional vorticity components and their interactions with the spanwise vortices, but still shed in synchronization along the spanwise direction. In regime III,the typical Kármán vortices partially or totally disappear,and some new vortex shedding patterns appear, such as-type, obliquely shedding, and crossed spanwise vortices with opposite sign. Corresponding to these complex vortex shedding patterns in the near wake, the fluid forces no longer oscillate regularly at a single vortex shedding frequency, but rather with a lower modulation frequency and multiple amplitudes. An overview of these flow regimes is presented.

INVESTIGATION OF VORTEX SHEDDING INDUCED HYDRODYNAMIC VIBRATION IN VORTEX STREET FLOWMETER

Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability However,in unsteady flow measurement,the pressure disturbance as well as the noise from the system or surrounding can reduce the signal to noise ratio of the flowmeter seriously Aimed to use vortex street flowmeters in unsteady flow measurement,the characteristics of the vortex shedding induced hydrodynamic vibration around the prism bluff body in a vortex street flowmeter are investigated numerically and by expriments The results show that the hydrodynamic vibrations with 180° phase shift occur at the axisymmetric points of the channel around the bluff body The most intense vibration occurs at the points on the lateral faces close to the base of the prism The results provide therefore a useful reference for developing an anti interference vortex flowmeter using the different ial sensing technique.

Inhibitory role of TACE/ADAM17 cytotail in protein ectodomain shedding

AIM:To determine if the cytotail of the principal sheddase tumor necrosis factor-α converting enzyme (TACE;ADAM17) controls protein ectodomain shedding.METHODS:Site-directed mutagenesis was performed to derive TACE variants. The resulting TACE expression plasmids with amino acid substitutions in the extracel-lular,cysteine-rich disintegrin domain (CRD) and/or deleted cytotail,along with an expression vector for the enhanced green fluorescence protein were transfected into shedding-defective M1 mutants stably expressing transmembrane L-selectin or transforming growth factor (TGF)-α. The expression levels of the TACE substrates at the cell surface were determined by flow cytometry. RESULTS:Consistent with published data,a single point mutation (C600Y) in the CRD led to shedding defi-ciency. However,removal of the cytotail from the C600Y TACE variant partially restored ectodomain cleavage of TGF-α and L-selectin. Cytotail-deleted mutants with any other substituting amino acid residues in place of Cys600 displayed similar function compared with tail-less C600Y TACE.CONCLUSION:The cytotail plays an inhibitory role,which becomes evident when it is removed from an enzyme with another mutation that affects the enzyme function.

The transmembrane domain of TACE regulates protein ectodomain shedding

Numerous membrane proteins are cleaved by tumor necrosis factor-α converting enzyme （TACE）, which causes the release of their ectodomains. An ADAM （a disintegrin and metalloprotease domain） family member, TACE contains several noncatalytic domains whose roles in ectodomain shedding have yet to be fully resolved. Here, we have explored the function of the transmembrane domain （TM） of TACE by coupling molecular engineering and functional analysis. A TM-free TACE construct that is anchored to the plasma membrane by a glycosylphosphatidylinositol （GPI）-binding polypeptide failed to restore shedding of transforming growth factor-or （TGF-α）, tumor necrosis factor-α （TNF-α） and L-selectin in cells lacking endogenous TACE activity. Substitution of the TACE TM with that of the prolactin receptor or platelet-derived growth factor receptor （PDGFR） also resulted in severe loss of TGF-α shedding, but had no effects on the cleavage of TNF-α and L-selectin. Replacement of the TM in TGF-α with that of L-selectin enabled TGF-α shedding by the TACE mutants carrying the TM of prolactin receptor and PDGFR. Taken together, our observations suggest that anchorage of TACE to the lipid bilayer through a TM is required for efficient cleavage of a broad spectrum of substrates, and that the amino-acid sequence of TACE TM may play a role in regulatory specificity among TACE substrates.

Experimental Investigation on Cavitating Flow Shedding over an Axisymmetric Blunt Body

Nowadays,most researchers focus on the cavity shedding mechanisms of unsteady cavitating flows over different objects,such as 2D/3D hydrofoils,venturi-type section,axisymmetric bodies with different headforms,and so on.But few of them pay attention to the differences of cavity shedding modality under different cavitation numbers in unsteady cavitating flows over the same object.In the present study,two kinds of shedding patterns are investigated experimentally.A high speed camera system is used to observe the cavitating flows over an axisymmetric blunt body and the velocity fields are measured by a particle image velocimetry（PIV）technique in a water tunnel for different cavitation conditions.The U-type cavitating vortex shedding is observed in unsteady cavitating flows.When the cavitation number is 0.7,there is a large scale cavity rolling up and shedding,which cause the instability and dramatic fluctuation of the flows,while at cavitation number of 0.6,the detached cavities can be conjunct with the attached part to induce the break-off behavior again at the tail of the attached cavity,as a result,the final shedding is in the form of small scale cavity and keeps a relatively steady flow field.It is also found that the interaction between the re-entrant flow and the attached cavity plays an important role in the unsteady cavity shedding modality.When the attached cavity scale is insufficient to overcome the re-entrant flow,it deserves the large cavity rolling up and shedding just as that at cavitation number of 0.7.Otherwise,the re-entrant flow is defeated by large enough cavity to induce the cavity-combined process and small scale cavity vortexes shedding just as that of the cavitation number of0.6.This research shows the details of two different cavity shedding modalities which is worthful and meaningful for the further study of unsteady cavitation.

Dynamic Characteristics Analysis of Ice-Adhesion Transmission Tower-Line System under Effect of Wind-Induced Ice Shedding

The tower line system will be in an unsafe status due to uniform or uneven fall of ice coating which is attached to the surface of tower and lines.The fall of ice could be caused by wind action or thermal force.In order to study the dynamic characteristics of the self-failure of the transmission line under the action of dynamicwind load,a finite elementmodel of the two-span transmission tower line system was established.The birth and death element methods are used to simulate the icing and shedding of the line.Tensile failure strength is the shedding criterion for ice coating.The fluctuating wind speed time history of the tower line systemis first simulated,and then the fluctuating wind and the average wind are superimposed to generate the instantaneous wind speed and converted into wind load.The dynamic response of the transmission tower line systemunder iced coupling with different wind speeds and different thicknesses of ice coating was studied.This is the first attempt that the coupling dynamic response of the icing shedding and wind load for the transmission tower-line system is discussed in this paper.In addition,the dynamic characteristics of wind are included.In particular,the limiting mechanical conditions are considered.According to the simulation results,it is found:because of the ice shedding,the stress of the conductor changes obviously in the first 20 seconds,and the ground wire changes sharply in the first two seconds;the icing of the conductor(ground)wire is gradually deicing under the action of wind vibration;the displacement of tower top increases with the increase of wind speed and icing thickness.

Virus load and virus shedding of SARS-CoV-2 and their impact onpatient outcomes

BACKGROUND Understanding a virus shedding patterns in body fluids/secretions is importantto determine the samples to be used for diagnosis and to formulate infectioncontrol measures.AIM To investigate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)shedding patterns and its risk factors.METHODS All laboratory-confirmed coronavirus disease 2019 patients with completemedical records admitted to the Shenzhen Third People’s Hospital from January28, 2020 to March 8, 2020 were included. Among 145 patients (54.5% males;median age, 46.1 years), three (2.1%) died. The bronco-alveolar lavage fluid(BALF) had the highest virus load compared with the other samples. The viralload peaked at admission (3.3 × 108 copies) and sharply decreased 10 d afteradmission.RESULTS The viral load was associated with prolonged intensive care unit (ICU) duration.Patients in the ICU had significantly longer shedding time compared to those inthe wards (P < 0.0001). Age > 60 years [hazard ratio (HR) = 0.6;95% confidenceinterval (CI): 0.4-0.9] was an independent risk factor for SARS-CoV-2 shedding,while chloroquine (HR = 22.8;95%CI: 2.3-224.6) was a protective factor.CONCLUSION BALF had the highest SARS-CoV-2 load. Elderly patients had higher virus loads,which was associated with a prolonged ICU stay. Chloroquine was associatedwith shorter shedding duration and increased the chance of viral negativity.

Determination of Effective Load Shedding Schemes in Electric Power Plants

The ability of power system to survive the transition from preloading state to the gradual increase in load and thereafter reach an acceptable operational condition is an indication of transient stability of the system. The study analyzed load shedding scheme through the use of empirical measurement tools and load-flow simulation techniques. It was geared towards determining effective load shedding strategies to reduce unnecessary overload in order to achieve dynamic stability of the electric power network in the Export Free Trade Zone, Calabar, Nigeria. From the tests and the measurements taken, it was observed that the real and reactive powers from the generator and the mechanical power from the turbine engine were stable when the load shedding controller was switched on, as compared to when it was off. The engine speed, the bus-bar frequency and the output voltage of the generator stabilized within a shorter time (about 8 seconds) when the controller was switched on than when it was on the off condition. Also, there were noticeable fluctuations in the speed of the remaining two generators. It became stable at about 12 seconds after the loss. The variations were 0.3 per cent of the nominal speed value. The excitation voltage fluctuated from 1.2 (pu) to 4.5 (pu) when the bus voltage dipped as a result of additional load. It then came down and stabilized at 1.8 (pu) after few swings. This confirmed that the stability of power system is much enhanced when load shedding controllers are effectively configured on the network.

Role of ADAM10 and ADAM17 in CD16b Shedding Mediated by Different Stimulators

Objective To investigate the main proteinases responsible for CD16b shedding under different stimulators. Methods HEK293 cell line stably expressing CD16b was constructed by lentivirus system. The cell line was then overexpressed with a disintegrin and metalloproteinase 10 （ADAM10） or ADAM17, sup- pressed with short hairpin RNA of ADAM10 or ADAM I 7, and reconstituted with ADAM 10 or ADAM17, respectively. After each treatment, the cell line was stimulated with ionomycin or phorbol 12-myristate- 13-acetate （PMA） for 12 hours. The soluble CD 16b released from cell membrane was detected by immuno- precipition and immunoblot. Quantitation was then implemented to compare the amount of soluble CD 16b in cell supernatant after stimulation. Results HEK293 cell line stably expressing CD16b was successfully established. When CDI6b ex- pressing cell line was overexpressed with ADAM 10, shedding of CD 16b was increased after stimulation with ionomycin but not PMA; when the cell line overexpressed with ADAM I7, shedding of CDI6b was increased after stimulation with PMA but not ionomycin. Similarly, when ADAM10 was suppressed by short hairpin RNA, CD 16b shedding was decreased after stimulation with ionomycin; when ADAM 17 was suppressed by short hairpin RNA, CD16b shedding was decreased after stimulation with PMA. The shedding of CD16b was increased again when CD16b expressing cell line was reconstituted with ADAM10 and stimulated by ionomycin or reconstituted with ADAM 17 and stimulated by PMA. Conclusions Both ADAM10 and ADAM17 could shed CD16b, but they possess differed prefer- ences. ADAM10 is the main sheddase under stimulation of ionomycin, while ADAM17 is the main sheddase under stimulation of PMA.

High fecal calprotectin levels are associated with SARS-CoV-2 intestinal shedding in COVID-19 patients:A proof-of-concept study

BACKGROUND One third of coronavirus disease 2019(COVID-19)patients have gastrointestinal symptoms.Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)RNA has been detected in stool samples of approximately 50%of COVID-19 individuals.Fecal calprotectin is a marker of gastrointestinal inflammation in the general population.AIM To investigate if fecal calprotectin correlates with SARS-CoV-2 intestinal shedding in COVID-19 patients with pneumonia.METHODS Patients with SARS-CoV-2 pneumonia admitted to the Infectious Disease Unit(University Hospital of Trieste,Italy)from September to November 2020 were consecutively enrolled in the study.Fecal samples were collected and analyzed for quantification of fecal calprotectin(normal value<50 mg/kg)and SARS-CoV-2 RNA presence by polymerase chain reaction(PCR).Inter-group differences were determined between patients with and without diarrhea and patients with and without detection of fecal SARS-CoV-2.RESULTS We enrolled 51 adults(40 males)with SARS-CoV-2 pneumonia.Ten patients(20%)presented with diarrhea.Real-time-PCR of SARS-CoV-2 in stools was positive in 39 patients(76%),in all patients with diarrhea(100%)and in more than two thirds(29/41,71%)of patients without diarrhea.Obesity was one of the most common comorbidities(13 patients,25%);all obese patients(100%)(P=0.021)tested positive for fecal SARS-CoV-2.Median fecal calprotectin levels were 60 mg/kg[interquartile range(IQR)21;108];higher fecal calprotectin levels were found in the group with SARS-CoV-2 in stools(74 mg/kg,IQR 29;132.5)compared to the group without SARS-CoV-2(39 mg/kg,IQR 14;71)(P<0.001).CONCLUSION High fecal calprotectin levels among COVID-19 patients correlate with SARSCoV-2 detection in stools supporting the hypothesis that this virus can lead to bowel inflammation and potentially to the‘leaky gut’syndrome.

INVESTIGATION OF DOMINANT FREQUENCIES IN TRANSITION REYNOLDS NUMBER RANGE OF FLOW AROUND A CIRCULAR CYLINDER PARTⅡ: THEORETICAL DETERMINATION OF THE RELATIONSHIP BETWEEN VORTEX SHEDDING AND TRANSITION FREQUENCIES AT DIFFERENT REYNOLDS NUMBERS

An attempt has been made to explore whether the power relation can be obtained from theoretical considerations. The classical laminar and turbulent boundary layer concepts have been employed to determine appropriate values of the scaling lengths associated with vortex shedding and shear layer frequencies to predict the power law relationship with Reynolds number. The predicted results are in good agreement with experimental results. The findings will provide a greater insight into the overall phenomenon involved.

Comparable outcomes but higher risks of prolonged viral RNA shedding duration and secondary infection in cancer survivors with COVID-19: A multi-center, matched retrospective cohort study

Results Sixty-one cancer survivors and 183 matched non-cancer patients were screened from 2,828 COVID-19 infected patients admitted to 4 hospitals in Wuhan,China.The median ages of the cancer survivor cohort and non-cancer patient cohort were 64.0(55.0–73.0)and 64.0(54.0–73.5),respectively(P=0.909).Cancer survivors reported a higher incidence of symptom onset than non-cancer patients.Fever(80.3%vs.65.0%;P=0.026)was the most prevalent symptom,followed by cough(65.6%vs.37.7%;P<0.001),myalgia,and fatigue(45.9%vs.13.6%;P<0.001).The risks of the development of severe events(adjusted hazard ratio[AHR]=1.25;95%confidence interval[CI]:0.76–2.06;P=0.378)and mortality(relative risk[RR]=0.90,95%CI:0.79–1.04;P=0.416)in the cancer survivor cohort were comparable to those of the matched non-cancer patient cohort.However,the cancer survivor cohort showed a higher incidence of secondary infection(52.5%vs.30.1%;RR=1.47,95%CI:1.11–1.95;P=0.002)and a prolonged viral RNA shedding duration(32 days[IQR 26.0–46.0]vs.24.0 days[IQR 18.0–33.0];AHR=0.54;95%CI:0.38–0.80;P<0.05).Conclusion Compared to non-cancer patients,cancer survivors with COVID-19 exhibited a higher incidence of secondary infection,a prolonged period of viral shedding,but comparable risks of the development of severe events and mortality.It is helpful for clinicians to take tailored measures to treat cancer survivors with COVID-19.

类风湿性关节炎滑膜病变高频超声表现与Anti-ccp、ESR及CRP的相关性

目的分析类风湿性关节炎(RA)滑膜病变高频超声表现与抗环瓜氨酸肽抗体(Anti-CCP)、红细胞沉降率(ESR)和C反应蛋白(CRP)的相关性,以期为该疾病早期诊断及治疗方案的制定提供更为准确和科学的依据。方法选取2020年1月至2023年3月于大庆龙南医院风湿免疫科住院的治疗前RA患者65例(RA组),另选取同期于本院体检中心行体检的健康者55名(对照组)。比较两组高频超声表现、髌上囊液体厚度、滑膜厚度、滑膜动脉RI及实验室指标(Anti-ccp、ESR及CRP水平),RA组根据Anti-ccp、ESR及CRP阳性标准分为阳性、阴性组,比较Anti-ccp、ESR及CRP阳性及阴性组的髌上囊液体厚度、滑膜厚度、滑膜动脉RI。采用Pearson分析滑膜病变高频超声表现各指标与Anti-ccp、ESR及CRP的相关性。结果对照组膝积液少<4 mm;RA组80%膝积液>4 mm,多对称,尤见于内外侧隐窝。对照组滑膜难辨,RA组滑膜增厚、低回声、分界清、表面糙、见绒毛。彩超示RA组81.53%膝滑膜有明显血流信号,多为Ⅱ、Ⅲ级。RA组髌上囊液体厚度、滑膜厚度、Anti-ccp、ESR及CRP水平均高于对照组,滑膜动脉RI则低于对照组,差异有统计学意义(P<0.05);Anti-ccp、ESR及CRP阳性组髌上囊液体厚度、滑膜厚度水平均显著高于阴性组,滑膜动脉RI低于阴性组,差异有统计学意义(P<0.05)。髌上囊液体厚度、滑膜厚度与Anti-ccp、ESR及CRP水平均呈正相关(P<0.05);滑膜动脉RI与Anti-ccp、ESR及CRP水平均呈负相关(P<0.05)。结论高频超声可清晰观察RA患者的滑膜病变情况,且与Anti-ccp、ESR及CRP等实验室指标存在显著关联性,可为临床诊断RA滑膜病变患者提供有力的参考依据,利于制定更具针对性的治疗措施。

THE DESIGN OF A NEW OUTSIDE TYPE CONJUGATE CAMS FOR SHEDDING MECHANISM

In the usual shedding mechanism of a weaving loom, the conjugate type of cams can be designed precisely according to any regular pattern sequence of heald frame motion to suit the weaving technological requirements. As this mechanism is also quite simple, with smaller cam size and better technological function, it is therefore very important and worthwhile to study this type of conjugate cams. In this paper, we try to analyze the defects of the traditional and some abroad type outside conjugate cams shedding mechanism, and propose a new improved design of this type of conjugate cams and then work it out finally.