Effect of Multiple Coatings of One-step Self-etching Adhesive on Microtensile Bond Strength to Primary Dentin

Objective To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin.Methods Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each.In group 1,each tooth was hemisected into two halves.One half was assigned to control subgroup 1,which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing.In group 2,the teeth were also hemisected into two halves.One half was assigned to control subgroup 2,which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions;the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer.Microtensile bond strength was immediately tested after specimen preparation.Results When the adhesive was applied three times before light curing,the bond strength of the experimental subgroup 1(n=33,57.49±11.61 MPa) was higher than that of the control subgroup 1(n=31,49.71±11.43 MPa,P<0.05).When using the technique of applying multiple layers of adhesive with light curing each successive layer,no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2(P>0.05).Conclusion Multiple coatings of one-step self-etching adhesive can increase the immediate bond strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

Multiple Coatings can Improve the Bond Durability of One-step Self-etching Adhesive to Primary Dentin

Objective To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin. Methods Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instruc- tions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer＇s instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaC1 containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis. Results When the adhesive was applied three times before light curing, the bond strength of the ex- perimental subgroup 1 was significantly higher than that of the control subgroup 1 （47.46__＋13.91 vs. 38.12＋11.21 MPa, P〈O.05）. When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup （39.40＋8.87 vs. 40.87-＋9.33 MPa, P〉O.05）. Conclusion Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

Passive smart self-repairing concrete beams by using shape memory alloy wires and fibers containing adhesives

An innovative approach to increase structural survivability of concrete and maintain structural durability of concrete was developed in case of earthquakes and typhoons. This approach takes advantage of the superelastic effect of shape memory alloy(SMA) and the cohering characteristic of repairing adhesive. These SMA wires and brittle fibers containing adhesives were embedded into concrete beams during concrete casting to form smart reinforced concrete beams. The self-repairing capacity of smart concrete beams was investigated by three-point bending tests. The experimental results show that SMA wires add self-restoration capacity,the concrete beams recover almost completely after incurring an extremely large deflection and the cracks are closed almost completely by the recovery forces of SMA wires. The number or areas of SMA wires has no influence on the tendency of deformation during loading and the tendency of reversion by the superelasticity. The adhesives released from the broken-open fibers fill voids and cracks. The repaired damage enables continued function and prevents further degradation.

Sciatic nerve repair using adhesive bonding and a modified conduit

When repairing nerves with adhesives, most researchers place glue directly on the nerve stumps, but this method does not fix the nerve ends well and allows glue to easily invade the nerve ends. In this study, we established a rat model of completely transected sciatic nerve injury and re- paired it using a modified 1 cm-length conduit with inner diameter of 1.5 mm. Each end of the cylindrical conduit contains a short linear channel, while the enclosed central tube protects the nerve ends well Nerves were repaired with 2-octyl-cyanoacrylate and suture, which complement the function of the modified conduit. The results demonstrated that for the same conduit, the av- erage operation time using the adhesive method was much shorter than with the suture method. No significant differences were found between the two groups in sciatic function index, motor evoked potential latency, motor evoked potential amplitude, muscular recovery rate, number of medullated nerve fibers, axon diameter, or medullary sheath thickness. Thus, the adhesive method for repairing nerves using a modified conduit is feasible and effective, and reduces the operation time while providing an equivalent repair effect.

Skin-Adhesive Tape versus Interrupted Suture in Episiotomy Skin Repair: Randomized Control Trial

Introduction: The ideal method for perineal repair should be quick, easy to perform and preferably, with minimal pain. Aim: To compare skin adhesive tape and interrupted?absorbable subcuticular suture for episiotomy repair after birth as regard postoperative pain, skin closure time and wound infection. Design: Prospective double-blinded randomized controlled trial. Methods: Three-hundred qualified patients were equally distributed between two groups. Group 1 underwent skin repair with skin adhesive tape, while group 2 underwent the currently traditional method for perineal repair by interrupted suture. Pain was evaluated at 2, 4, 6 and 12 hours after birth then daily until one week using Wong-Baker faces pain rating scale with verbal expression for pain intensity as primary outcome. Skin closure time and wound infection were also evaluated as secondary outcomes. Results: Statistically significant difference in pain was?found at 4 and 6 hours, and 3,?4,?5 and 7 days after perineal repair in favor of the adhesive tape group (p = 0.04 and 0.02 respectively) (p = 0.002, 0.002, 0.003 and 0.001 respectively). No statistically significant difference was found in skin closure time between both groups, and no cases of wound infection occurred in both groups (p = 0.3). Conclusion: Skin adhesive tape may be superior to skin suturing in decreasing pain resulting from perineal repair after birth;however, further studies are needed to assess long-term effects, calculate costs and accurately measure patients’ satisfaction, which were not addressed in this study.

Fracture analysis of cracked metallic plate repaired with adhesive bonding composite patch

Fatigue crack growth test of cracked metallic plate repaired with adhesive bonding composite patch was conducted to study the fracture behavior of crack patching. The failure mode was that crack grows along with adhesive debonding. The crack length and debonding area were measured at different numbers of cycles. The nonlinear three- dimensional(3D)finite element(FE)model considering adhesive debonding and crack growth simultaneously was developed. The experimental and analytical results were in good agreement with each other.

The Crack Self-healing Properties of Cement-based Material with EVA Heat-melt Adhesive

An experimental program was carried out to investigate whether EVA （ethylene vinyl acetate copolymer） heat-melt adhesive can potentially act as a self-healing agent in cement-based material. The effects of incorporation of EVA and heating on the properties of mortar were studied. Self-healing capacity of EVA specimens was also verified. The experimental results show that the addition of EVA would not greatly affect original characteristics of the matrix when EVA content was less than 5%; the interface between EVA and cement matrix was well improved after heating, which allows a significant improvement in flexural strength and toughness of specimen; pre-damaged specimens in various degrees （30%, 50% and 70%） were effectively repaired by EVA and the repair efficiency all exceeded 100%.

活性改性剂合成及其对环氧胶黏剂力学与界面粘接性能的影响

综合考虑环氧胶黏剂的施工性能、力学性能及与砂浆界面的粘接性能,利用三羟甲基丙烷三缩水甘油醚(TMPGE)与1,4-丁二醇(BDO),通过控制反应物物质的量比以及反应时间制备了四种低环氧值兼具高羟基含量的预聚体(PPM)。通过1H-NMR、盐酸-丙酮法及凝胶渗透色谱(GPC)对PPM进行了表征。进一步研究了PPM对改性环氧胶黏剂工作性能、固化力学性能、与水泥砂浆粘接强度以及表面性质的影响。结果显示:延长反应时间以及增加BDO用量使PPM的数均分子量更大、环氧值更低。四种PPM改性后,胶黏剂的放热峰值温度降低,可操作时间延长。同时,PPM使环氧固化物的延性显著增加。四种PPM改性后使环氧与水的接触角降低,固化物表面的极性组分升高。XPS分析表明,PPM使环氧固化物的羟基含量显著提高。最后,PPM使胶黏剂对湿砂浆基体的粘接强度提高了一倍以上。

重组贻贝粘蛋白在点阵CO_(2)激光治疗面部痤疮萎缩性瘢痕术后创面修复中的应用研究

目的:探究重组贻贝粘蛋白水凝胶敷料(Recombined mussel adhesive protein hydrogel dressing,Rmaphd)在点阵CO_(2)激光治疗面部痤疮萎缩性瘢痕术后创面修复中的应用效果。方法:选择2022年6月-2023年2月面部痤疮萎缩性瘢痕患者117例,分为Rmaphd组、重组人表皮生长因子(Recombinant human epidermal growth factor,rhEGF)组和对照组,每组39例,三组均给予点阵CO_(2)激光术治疗,术后分别给予Rmaphd、rhEGF及生理盐水处理,比较三组疗效、ECCA评分、症状持续时间以及生活质量评分。结果:Rmaphd组和rhEGF组总有效率分别为92.31%和94.87%,均高于对照组76.92%(P<0.05),术后ECCA评分低于对照组(P<0.05),术后疼痛、红斑、痂皮持续时间短于对照组(P<0.05),Acne-QoL各指标得分优于对照组(P<0.05);上述各临床Rmaphd组与rhEGF组差异无统计学意义(P>0.05)。结论:Rmaphd用于点阵CO_(2)激光治疗面部痤疮萎缩性瘢痕术后创面修复疗效显著,具备在临床上辅助激光治疗术后修复的应用潜力。

局部带蒂黏膜附着龈重建术和游离龈移植术在口腔种植修复中的疗效

目的探讨局部带蒂黏膜附着龈重建术和游离龈移植术在口腔种植修复中的临床疗效。方法回顾性分析2018年10月至2020年10月收治的92例口腔种植修复患者的病案资料,根据手术治疗方式选择情况的不同,分为重建组(n=46,采取局部带蒂黏膜附着龈重建术)和游离组(n=46,采取游离龈移植术)。评价2种治疗方式的临床效果,比较2组手术前后的菌斑指数、视觉模拟评分(VAS)、出血指数、角化龈宽度。结果2组口腔种植修复患者的种植成功率比较,差异无统计学意义(P>0.05)。重建组术后3、6个月菌斑指数,术后1周VAS评分,术后3个月出血指数与游离组,差异无统计学意义(P>0.05);2组术后菌斑指数、VAS评分、出血指数较术前均显著下降(P<0.05)。重建组术后3、6个月的角化龈宽度低于游离组(P<0.05)。结论局部带蒂黏膜附着龈重建术和游离龈移植术在口腔移植修复中均能达到显著效果,利于种植牙移植固定,且术后菌斑指数、VAS评分、出血指数均显著下降,但后者角化龈宽度移植效果更显著,两种术式各有优劣势,应结合患者具体病情合理选择适宜术式。

宫腔粘连中水凝胶促内膜修复的研究与进展

背景:防止宫腔粘连复发的关键是重建具有正常功能的子宫内膜,国内外对于宫腔粘连复发治疗的最新突破在于利用可降解材料制备水凝胶类物质防止粘连复发。目的:综述宫腔粘连中水凝胶促内膜修复的研究进展。方法:系统检索PubMed数据库、Web of Science、中国知网、万方数据库,以“宫腔粘连,子宫内膜损伤,子宫内膜再生,水凝胶,Intrauterine adhesions,Endometrial injury,Endometrium regeneration,hydrogel”为关键词,收集各数据库1990年1月至2023年3月发表的相关文献。结果与结论:近年来国内外关于宫腔粘连中水凝胶促内膜修复的研究取得了一定进展,对于宫腔粘连的防治和促进内膜修复具有重要作用:①水凝胶作为组织工程中一大重要载体,它本身具有优秀的生物相容性、生物降解性和三维网状结构,可以更好地应用在宫腔粘连治疗中;②以水凝胶为基础的搭载体系,可以通过运输药物/生物制剂/干细胞来促进子宫内膜上皮细胞的增殖分化,并恢复正常子宫形态,防止粘连复发;③透明质酸类水凝胶在满足良好生物相容性的同时还可以促进内膜上皮细胞的增殖分化,且在子宫内会被相应的酶类物质水解,不会影响机体正常代谢,是目前临床常用的子宫防粘连剂,也是组织工程研究中最常用的一种水凝胶载体;④以温敏特性出众的泊洛沙姆水凝胶可以在进入体内迅速凝胶化,快速形成物理屏障,并可对搭载物质起到缓释作用和提供细胞生长/黏附平台;⑤利用不同特性材料制备治疗性水凝胶的前景广阔,比如温敏特性水凝胶、pH响应性水凝胶以及光敏水凝胶等,但还存在诸多问题需要解决,例如水凝胶体系的安全性以及降解产物是否引起免疫反应、对正常机体经期是否具有影响等问题,还需要大量动物实验及临床试验来验证其安全性和有效性,不断完善治疗策略。

复合材料修补前后拉伸损伤的非线性超声Lamb波检测

为了确保复合材料修补结构后续的稳定性,需要利用非线性超声Lamb波对修补后的部位进行健康检测。利用非线性超声Lamb波高次谐波响应技术,对复合材料板胶接修补前后的拉伸损伤进行了实验与仿真研究。通过ABAQUS软件进行有限元建模,采用Hashin准则预测基体拉伸损伤演化,并在拉伸过程中引入平滑分析步,最后通过施加位移载荷模拟Lamb波的传播过程,在实验验证仿真模型可行性的基础上,研究非线性Lamb波高次谐波响应与拉伸位移之间的关系,以及不同拉伸损伤程度对非线性系数的影响。结果表明:与未修补结构相比,经过拉伸后胶接修补结构的损伤面积与二次、三次非线性系数明显降低,说明该方法可以评估工程胶接修补的有效性;随着拉伸位移的增加,二次、三次谐波幅值和非线性系数先增加后减小,在拉伸位移为1 mm时达到最大;借助非线性Lamb波高次谐波技术能够有效地对复合材料修补前后的拉伸损伤程度进行预测。

基于超声导波相位延迟的胶接修补结构脱粘监测

胶接修补是修复受损结构的主要手段之一,但修补后的结构在疲劳载荷或极端环境等因素作用下容易再次产生脱粘损伤,从而影响结构的服役安全性。因此,需要对修补结构胶接界面处的脱粘损伤进行有效识别,本文提出了一种基于超声导波相位延迟变化的监测方法,首先采用多频率融合概率加权分布损伤诊断成像算法对脱粘损伤中心位置进行综合定位,然后通过相位延迟损伤因子与路径脱粘长度之间的关系来确定各个含损伤路径的脱粘边缘点,进而勾画出边缘点的凸包络曲线用于脱粘损伤轮廓识别。通过有限元仿真分析验证了该方法对脱粘损伤中心位置和形状识别的准确性,并在复合材料补片修补铝板结构试验件上开展试验进一步证明了该方法的有效性,从而可为胶接修补结构的安全使用评估提供实用的监测手段。

3D打印水凝胶支架在宫腔粘连防治中的应用

宫腔粘连(intrauterine adhesion,IUA)常易引发停经、不孕和复发性流产等问题,严重影响女性身心健康。临床上,对IUA的治疗主要采用手术分离方式,术后易复发,治疗效果欠佳。3D生物打印支架成为治疗IUA的前沿领域,可分隔受损区域防止粘连形成,体内可控降解无需手术取出。该支架可用于药物负载、干细胞移植及外泌体的递送,可将药物或生长因子释放到损伤区域,促进组织修复与再生。将负载干细胞或干细胞外泌体的3D打印水凝胶移植到损伤区域,可有效促进IUA的修复并改善妊娠率。3D生物打印可为患者提供个体化治疗方案,联合干细胞或干细胞外泌体的治疗策略有望成为治疗IUA的有力工具。

HAMSCs移植联合G-CSF有效修复IUA大鼠子宫内膜损伤并抑制其纤维化

目的探讨人羊膜间充质干细胞(HAMSCs)联合粒细胞集落刺激因子(G-CSF)对宫腔粘连(IUA)大鼠子宫内膜损伤后的修复及纤维化抑制的影响。方法酶消化法提取HAMSCs体外培养,取P3代细胞通过生长特征、免疫荧光鉴定表面标记分子和三系分化能力进行鉴定。32只动情期SD大鼠随机均分为IUA组、HAMSCs组、G-CSF和H+G组。乙醚麻醉后行背部开口,IUA组从近卵巢端向左侧子宫腔内注射1 mL无水乙醇作用90 s,1 mL生理盐水冲刷子宫2次,右侧子宫注射等体积生理盐水作为假手术自身对照(Sham对照)。在造模后第7天和第10天进行2次治疗,每次注射体积均为0.2 mL。其中IUA组注射PBS,HAMSCs组宫腔灌注含1×106个细胞的PBS;G-CSF组灌注含20μg G-CSF的PBS;H+G组则在G-CSF灌注后再行HAMSCs灌注。各组大鼠在第2次治疗结束7 d后处死取子宫角备用。HE、Masson染色法检测各组大鼠子宫内膜的修复情况;qRT-PCR和免疫组化法检测各组大鼠子宫中TGF-β1、SMAD3、SMAD7、β-catenin、孕酮受体(PR)及雌激素受体(ER)的表达情况;另取32只大鼠同样分组造模后与正常雄鼠交配,计算其怀孕率和胚胎数。结果所获细胞经生长特性、细胞表面分子和分化能力的鉴定符合MSCs特征。IUA组大鼠子宫出现水肿、充血等现象,其余各组大鼠子宫形态均在一定程度上得以恢复,子宫内膜厚度和腺体数目从高到低依次为Sham对照、H+G组、HAMSCs组、G-CSF组、IUA组。Masson染色结果显示,在纤维化面积占整个子宫内膜面积的比例上,从高到低依次为IUA组、G-CSF组、HAMSCs组、H+G组、Sham对照。qRT-PCR结果显示,Sham对照TGF-β1、SMAD3和β-catenin mRNA最低,在IUA组中表达最高(P<0.05)。与IUA组相比,HAMSCs、G-CSF和H+G处理不同程度降低TGF-β1、SMAD3和β-catenin mRNA表达,尤其H+G组的表达水平接近于Sham对照水平(P<0.05)。SMAD7、PR和ER mRNA的表达趋势则与TGF-β1、SMAD3、β-catenin相反(P<0.05)。免疫组化结果显示,与IUA组相比,HAMSCs、G-CSF和H+G处理可以降低TGF-β1、SMAD3和β-catenin表达而升高SMAD7、PR和ER表达(P<0.05)。怀孕率和胚胎数计数结果显示,IUA组怀孕率为0,HAMSCs、G-CSF、H+G可以提高怀孕率和胚胎数(P<0.05)。结论HAMSCs移植及G-CSF宫腔灌注可能通过TGF-β1/SMAD3/β-catenin信号促进IUA大鼠子宫内膜损伤后的修复并抑制其纤维化,并且H+G处理的治疗效果优于单一的HAMSCs和单一G-CSF处理。

仿生物电刺激联合激素促进稽留流产后内膜修复和预防宫腔粘连的效果分析

目的探讨仿生物电刺激与雌孕激素联合促进稽留流产后子宫内膜修复和预防宫腔粘连的效果。方法选取2021年6月至2022年12月于深圳市南山区妇幼保健院治疗的稽留流产患者120例为研究对象,根据患者的入院顺序进行编号,按随机数字表法分为对照组(n=60)和联合组(n=60)。两组患者均在药物流产后行清宫术,对照组给予雌孕激素口服治疗,联合组在对照组的基础上联合仿生物电刺激治疗。比较两组患者术后腹痛持续时间、术后72h腹痛视觉模拟评分法(visual analogue scale,VAS)评分及术后当天、术后第15天、术后第1次月经来潮第15天的子宫内膜厚度、子宫螺旋动脉血流收缩末期峰值与舒张末期峰值的比值(end-systolic peak/end-diastolic peak,S/D)、搏动指数(pulsation index,PI)、阻力指数(resistance index,RI),并统计两组宫腔粘连的发生率。结果联合组患者术后腹痛持续时间和术后72h腹痛VAS评分均显著低于对照组(P<0.05)。联合组患者术后第15天、第1次月经来潮第15天的子宫内膜厚度均大于对照组,S/D、PI和RI均低于对照组(P<0.05)。治疗期间,联合组患者的宫腔粘连发生率为3.33%,对照组为13.33%,联合组显著低于对照组(P<0.05)。结论与单用雌孕激素治疗相比,仿生物电刺激联合雌孕激素修复稽留流产后患者的子宫内膜并预防宫腔粘连的效果更好,值得临床推广。

环氧树脂胶粘剂对混凝土裂缝修复性能的影响研究

研究使用环氧树脂胶粘剂修复混凝土裂缝问题,分析环氧树脂胶粘剂对于混凝土结构力学性能的影响,使用丁腈橡胶改性环氧树脂,增加环氧树脂韧性,并与稀释剂、固化剂混合制备修复混凝土的环氧树脂,将该环氧树脂灌注在预制裂缝的混凝土试件中,通过万能试验机等设备测试修复前后试件的抗压、抗折强度变化,并验证丁腈橡胶用量对于修复效果的影响。结果表明,使用改性环氧树脂修复混凝土多种形式的裂缝,能够提升混凝土抗压、抗折强度的恢复率,降低液体向混凝土入渗的速度,提升混凝土的性能,同时在环氧树脂中添加丁腈橡胶8 phr能够提升修复的耐水性。

三维有限元下后牙牙体缺损修复的研究现状

根管治疗后的牙齿脆性强、强度弱,在长期发挥咀嚼功能的过程中可能会造成牙体劈裂,磨牙最为明显,因此需要制作“冠类”修复体进行保护。随着修复材料及粘接技术的迭代更新,牙体缺损的修复方式日趋多样化、微创化。牙齿是行使咀嚼功能的受力器官,很多学者利用三维有限元分析法对牙体缺损的不同修复方式模拟受力分析,以期从材料力学角度对这些修复方式进行对比,为临床使用提供依据。本文就三维有限元分析法在牙体缺损修复所涉及的修复体种类、修复材料、粘接及垫底等方面的研究进行系统阐述。

Robust hydrogel adhesives for emergency rescue and gastric perforation repair

Development of biocompatible hydrogel adhesives with robust tissue adhesion to realize instant hemorrhage control and injury sealing,especially for emergency rescue and tissue repair,is still challenging.Herein,we report a potent hydrogel adhesive by free radical polymerization of N-acryloyl aspartic acid(AASP)in a facile and straightforward way.Through delicate adjustment of steric hindrance,the synergistic effect between interface interactions and cohesion energy can be achieved in PAASP hydrogel verified by X-ray photoelectron spectroscopy(XPS)analysis and simulation calculation compared to poly(N-acryloyl glutamic acid)(PAGLU)and poly(N-acryloyl amidomalonic acid)(PAAMI)hydrogels.The adhesion strength of the PAASP hydrogel could reach 120 kPa to firmly seal the broken organs to withstand the external force with persistent stability under physiological conditions,and rapid hemostasis in different hemorrhage models on mice is achieved using PAASP hydrogel as physical barrier.Furthermore,the paper-based Fe^(3+)transfer printing method is applied to construct PAASP-based Janus hydrogel patch with both adhesive and non-adhesive surfaces,by which simultaneous wound healing and postoperative anti-adhesion can be realized in gastric perforation model on mice.This advanced hydrogel may show vast potential as bio-adhesives for emergency rescue and tissue/organ repair.

术前血清雌二醇水平与中-重度宫腔粘连术后妊娠结局的相关性分析

目的:探讨宫腔镜下粘连分离术(TCRA)前1 d的血清雌二醇(E 2)水平与中-重度宫腔粘连(IUA)妊娠结局之间的关系。方法:提取并分析了2018年1月至2019年12月于空军军医大学第二附属医院确诊并接受TCRA的中-重度IUA患者的临床数据。主要结局指标是12个月随访期间的妊娠率,应用多元回归分析、平滑曲线拟合和递归算法分析。结果:在符合纳入标准的288例患者中,有222例符合标准,并最终被纳入分析。多元回归分析结果显示,术前1 d的E 2水平与TCRA后的妊娠率呈负相关(aOR 0.77,95%CI 0.63~0.93,P=0.0074)。递归算法分析结果显示,当术前血清E 2水平小于380.6 pmol/L时,每增加36.7 pmol/L,妊娠率就会降低约20%(aOR 0.78,95%CI 0.67~0.89,P=0.0004)。结论:术前血清E 2水平与中-重度IUA患者的妊娠结局呈负相关。