[Outcomes of partial pubectomy assisted anastomotic urethroplasty for male patients with pelvic fracture urethral distraction defect].

OBJECTIVE: To summarize the clinical outcomes of partial pubectomy assisted anastomotic urethroplasty for male patients with pelvic fracture urethral distraction defect (PFUDD) and discuss the skills of partial pubectomy. METHODS: The clinical data of 63 male patients with PFUDD were retrospective reviewed. The procedure of the anastomotic urethroplasty was as follows: (1) circumferentially mobilizing the bulbar urethra; (2) separating the corporal bodies; (3) performing the urethral anastomosis after partial pubectomy and exposure of the healthy two ends of the urethra. RESULTS: The mean age of the patients was (39.2±15.6) years (range: 15-72 years). The median time between incidents and operation was 15 months (range: 3-240 months) and the mean length of stricture was (3.85±0.91) cm (range: 1.5-5.5 cm). All the patients had undergone suprapubic cystostomy in acute setting. Thirteen patients (20.6%) were re-do cases and the patients who had undergone dilation, direct vision internal urethrotomy (DVIU), and open primary realignment were 22 (34.9%), 8 (12.7%), and 8 (12.7%), respectively. Assisted with partial pubectomy, the anastomotic urethroplasty had been successfully performed in all the patients. The mean time of operation was (160.2±28.1) min (110-210 min), and the mean evaluated blood loss was (261.1±130.3) mL (100-800 mL). There were 3 cases (4.8%) with perioperative blood transfusions. The postoperative complications were bleeding and urinary tract infection, which were controlled conservatively. The mean maximum urine flow rate was (23.7±7.4) mL/s (15.0-48.2 mL/s) after removing the catheters 4 weeks after urethroplasty. The median follow-up was 23 months (12-37 months). The urethroscopy showed 2 cases of stricture recurrences and 1 case of iatrogenic penile urethral stricture due the symptoms of urinary tract infection and decreased urine flow and all of them were successfully managed with dilation. CONCLUSION: Partial pubectomy can effectively reduce the gap between the ends of the urethra and promote tension-free anastomosis during the anastomotic urethroplsty for patients with PFUDD. The skills of the procedure include good exposure of the anterior surface of pubic symphysis between the separated corporal bodies, carefully mobilizing and securing the deep dorsal vein of the penis, removing the partial pubic bone and the harden scar beneath the pubic bone for good exposure of the proximal urethral end.

[Combined transperineal and transpubic urethroplasty for patients with complex male pelvic fracture urethral distraction defect].

OBJECTIVE: To evaluate the clinical effects and characteristics of combined transperineal and transpubic urethroplasty for patients with complex pelvic fracture urethral distraction defect (PFUDD). METHODS: We retrospectively reviewed the clinical data of 17 male patients with complex posterior PFUDD from January 2010 to December 2019. The complications included urethrorectal fistulas in 2 patients (11.8%), urethroperineal fistula in 1 patient (5.9%). Ten patients had undergone previous treatments: dilatation in 3 patients (17.6%), internal urethrotomy in 1 patient, failed urethroplasty in 6 patients (35.3%), of whom 2 patients had two times of failed urethroplasties. All the patients were performed with urethroplasty by combined transperineal and transpubic approach with removing the entire pubic bone followed by the anastomosis. RESULTS: The mean age of the patients included in this study was 35.5 (range: 21-62) years. The mean length of stricture was 5.5 (range: 4.5-7.0) cm, the mean follow-up was 27 (range: 7-110) months, the mean time of operation was 190 (range: 150-260) min, the mean evaluated blood loss was 460 (range: 200-1 200) mL. There were 5 patients who needed blood transfusion intraoperatively or postoperatively. Wound infection was seen in 4 out of 17 patients and thrombosis of lower extremities in 1 out of 17 patients. The last follow-up showed that the mean postoperative maximum urinary flow rate was 22.7 (range: 15.5-40.7) mL/s. After removing the catheter, one patient presented with decreased urinary flow and symptoms of urinary infection. Cystoscopy showed the recurrent anastomotic stricture, which was cured by internal urethrotomy. In our series, the success rate of the combined transperineal and transpubic urethroplasty was 94.1% (16/17). CONCLUSION: Combined transperineal and transpubic urtheroplasty can achieve a tension free anastomosis after removing the entire wedge of pubis in some patients with complex PFUDD. However, this procedure should be completed in a regional referral hospital due to the complexity of the operation and the high percentage of complications.

Wnt/beta-Catenin Signaling Contributes to Vincristine-Induced Neuropathic Pain.

Chemotherapy-induced neuropathic pain (CNP) is the major dose-limiting factor in cancer chemotherapy. However, the mechanisms underlying CNP remain elusive. In the present study, CNP was induced by repeated intraperitoneal injection of vincristine (VCR) into male C57BL/6J mice. VCR administration caused significant activation of Wnt/beta-catenin signaling, which led to the activation of astrocytes, microglia, the release of inflammatory cytokines tumour necrosis factor (TNF)-alpha, monocyte chemoattractant protein-1 (MCP-1) and the activation of subsequent mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinase (ERK) signaling pathway in CNP mice. Blocking Wnt/beta-catenin signaling by intrathecal administration of the inhibitors of Wnt response (IWR) effectively attenuated VCR-induced neuropathic pain. Furthermore, IWR inhibited the activation of astrocytes, microglia, TNF-alpha, MCP-1 and MAPK/ERK signaling in the spinal cord, which was triggered by VCR-induced Wnt/beta-catenin signaling upregulation. These results suggest that Wnt/beta-catenin signaling plays a critical role in VCR-induced neuropathic pain and provides evidence for potential interfering with Wnt/beta-catenin signaling to ameliorate VCR-induced neuropathic pain.

Comparison of hepatic epithelioid angiomyolipoma and non-hepatitis B, non-hepatitis C hepatocellular carcinoma on contrast-enhanced ultrasound.

PURPOSE: The purpose of this study was to retrospectively compare the imaging features of hepatic epithelioid angiomyolipoma (HEAML) to those of hepatocellular carcinoma negative for hepatitis B surface antigen and hepatitis C antibody (NBNC-HCC) on contrast-enhanced ultrasound (CEUS) with sulphur hexafluoride microbubbles. MATERIAL AND METHODS: Twenty-two patients (4 men, 18 women) with a mean age of 42.6±10.2 (SD) years (range: 22-63 years) with histopathologically confirmed HEMAL were included in the study. Forty-four patients (30 men, 14 women) with a mean age of 57.3±15.9 years (range: 19-85 years) with histopathologically confirmed NBNC-HCC were randomly selected from our institution's database as a control group. The CEUS characteristics of the two groups were compared. RESULTS: On conventional ultrasound, significant differences in tumor diameter were found between HEAML (4.0±2.0 [SD] cm; range: 1.3-8.9cm) and NBNC-HCC (8.4±4.4 [SD] cm; range: 1.6-18cm) (P<0.001) as well as in degrees of enhancement during the portal (P=0.001) and late phases (P=0.003), contrast distribution (P<0.001) and absence of pseudocaspule (P<0.001). On CEUS, hyperenhancement during the arterial phase was observed in 21/22 (95.5%) HEAMLs and in 43/44 (97.7%) NBNC-HCCs (P>0.999). Homogeneous enhancement was more frequent in HEAMLs (20/22; 90.9%) than in NBNC-HCCs (13/44; 29.6%) (P<0.001). Pseudocapsule was observed in 0/22 HEAMLs (0.0%) and in 36/44 NBNC-HCCs (81.8%) (P=0.017). A prolonged enhancement was observed in 5/22 HEAMLs (22.7%) and in 0/44 NBNC-HCCs (0.0%) (P<0.001) during the late phase. CONCLUSION: CEUS with sulphur hexafluoride microbubbles is helpful in discriminating between HEAML and NBNC-HCC. Homogeneous enhancement and lack of pseudocapsule are suggestive features for the diagnosis of HEAML.

Polar Metamaterials: A New Outlook on Resonance for Cloaking Applications.

Rotationally resonant metamaterials are leveraged to answer a longstanding question regarding the existence of transformation-invariant elastic materials and the ad hoc possibility of transformation-based passive cloaking in full plane elastodynamics. Combined with tailored lattice geometries, rotational resonance is found to induce a polar and chiral behavior, that is, a behavior lacking stress and mirror symmetries, respectively. The central, and simple, idea is that a population of rotating resonators can exert a density of body torques strong enough to modify the balance of angular momentum on which hang these symmetries. The obtained polar metamaterials are used as building blocks of a cloaking device. Numerical tests show satisfactory cloaking performance under pressure and shear probing waves, further coupled through a free boundary. The work sheds new light on the phenomenon of resonance in metamaterials and should help put transformation elastodynamics on equal footing with transformation acoustics and optics.

Development of a novel score to predict probability of growth without growth hormone after resection of paediatric craniopharyngiomas: relative to tumour growth pattern.

OBJECTIVE: Some patients with paediatric craniopharyngiomas (PCs) showed normal growth despite growth hormone deficiency, which is known as growth without GH (GWGH); however, its mechanism remains unclear. We aimed to develop a novel clinical score to predict the probability of GWGH in PCs. METHODS: A total of 708 PC patients were prospectively enrolled from six hospitals, among which 431 patients were finally included. Data from four of the six hospitals (n = 325) were used to develop the innovative clinical score (ICS), which was further validated using the data from the other two hospitals (n = 106). To establish and validate the ICS, sequential logistic regression was used to analyse the clinical characteristics including tumour growth pattern and tumour size and so on. Furthermore, C-statistic was employed to calibrate the discriminatory ability of the established clinical score, while a calibration plot was adopted for further assessment. RESULTS: The overall incidence of GWGH was 16.9% (73/431). The ICS ranged from 2 to 23, with an optimism-corrected C-statistic of 0.820, Furthermore, the optimism-corrected C-statistic of external validation was 0.835, indicating good discriminatory power and robustness of the clinical score. Additionally, no apparent overestimation or underestimation was observed in the calibration plots, which showed excellent calibration power of the clinical score. CONCLUSIONS: Based on tumour growth patterns and PC patients' clinical characteristics, individualized surgical strategies were promising to achieve long-term effective management of PC patients. The ICS is valuable for the evaluation of probability of developing postoperative GWGH. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT00949156.

[Single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap].

OBJECTIVE: To evaluate the clinical effect of single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap. METHODS: We retrospectively reviewed the clinical database of 22 male patients with penile urethral stricture who received single-stage repair using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap from November 2015 to October 2018. All the cases had no complications, such as skin fistula. The causes of stricture included iatrogenic (14/22, 63.6%), inflammation (2/22, 9.1%) and idiopathic (6/22, 27.3%). A ventral urethrotomy was made in the segment of stricture and extended proximally and distally until the normal calibre urethra was encountered. The oral mucosa graft was secured to the corpus spongiosum in dorsal onlay fashion or underlying corpora cavernosum after resection of the severe scarred urethra. Then the prepared Orandi fasciocutaneous penile skin flap was secured to edges of corpus spongiosum or oral mucosa graft. A 16 F or 14 F Foley catheter was left in situ for a minimum of 3 weeks, at which time a urethrogram was performed to look for extravasation, and the urethroscopy was performed if necessary. Success was defined as an open urethra with Qmax≥15 mL/s and no need for further surgical intervention. RESULTS: all the 22 patients with a mean age of 52.6 (18-73) years underwent the combined tissue-transfer technique. The mean length of the penile urethral stricture was 5.3 (2.5-10.0) cm and the mean preoperative Qmax was 6.7 mL/s. the mean length of oral mucosa grafts and fasciocutaneous skin flaps were 5.5 (3.2-10.5) cm and 6.0 (3.5-11.0) cm, respectively. The mean operation time was 225 (150-420) minutes and the mean evaluated blood loss was 53 (20.0-110.0) mL. The grafts included buccal mucosa (19/22, 86.4%) and lingual mucosa (3/22, 13.6%). The mean postoperative Q max was 21.2 (15-32) mL/s. A case of skin fistula and 2 cases of recurrent stricture were found, so the technique success rate was 81.8% (18/22) at a mean follow-up of 20.5 (5-51) months. The perioperative complications included 2 cases of infection and skin necrosis, which healed well after conservative treatment. CONCLUSION: Single-stage repair of penile urethral stricture using combined dorsal onlay oral mucosa grafting with ventral onlay penile skin flap appears to be an excellent option to repair penile urethral stricture with unsalvageable urethral plate and the penile skin is available. The present clinical series showed a successful rate of 81.8% (18/22).

[Application of closed negative pressure irrigation and suction device in the treatment of high perianal abscess].

Objective: To explore the efficacy of closed negative pressure irrigation and suction device (Patent number: Z200780013509.8) in the treatment of high perianal abscess. Methods: From January 2015 to December 2016, ≥18-year-old patients with primary high perianal abscess who were treated at our department were prospectively enrolled. Exclusion criteria: (1) recurrent perianal abscess; (2) complicated with anal fistula formation; (3) preoperative, intraoperative or postoperative physical therapy, and curettage treatment, negative pressure irrigation; (4) Crohn's disease-related perianal abscess; (5) with immunosuppressive status, such as transplant recipients; (6) co-existence of malignant tumors, such as leukemia; (7) with diabetes; (8) those who could not receive long-term follow-up and were not suitable to participate in this study. According to the random number table method, the patients were randomly divided into negative pressure irrigation and suction group and routine drainage group. All patients were clearly diagnosed and the location and size of the perianal abscess were marked before surgery. These two groups were treated as follows: (1) Negative pressure irrigation and suction group: the skin was incised at a diameter of 1-2 cm at the site where the abscess fluctuated most obviously. After the abscess was removed, a closed negative pressure irrigation and suction device was installed and the pressure of -200 to -100 mmHg (1 mmHg=0.133 kPa) was maintained to keep the abscess cavity collapsed. Generally, the irrigation was stopped 5 days later or when the drainage was clear. The closed vacuum suction was maintained for 2 additional days, before the wound was sutured. (2) Conventional drainage group: conventional incision and drainage was carried out. The skin was cut at a diameter of 8 to 10 cm at the site of abscess with most obvious fluctuation. After the abscess was removed, normal saline gauze was used for dressing. Dressing was changed regularly until the wound healed. The efficacy, operative time, intraoperative bleeding, incision length, frequency of dressing change, pain index (visual analogue score, VAS score), postoperative healing time, complications, recurrence rate of perianal abscess, anal fistula formation rate were observed. The t test and χ2 test were used for comparison between the 2 groups. Results: There were both 40 patients in the negative pressure irrigation and suction group and the conventional drainage group. There were 28 males and 12 females in negative pressure irrigation and suction group with a mean age of (38.3±12.0) years and mean disease course of (6.6±2.1) days. The abscess in pelvic-rectal space accounted for 50.0% (20/40) and the mean diameter of abscess was (8.0±3.7) cm. There were 26 males and 14 females in the conventional drainage group with a mean age of (37.1±11.8) years and mean disease course of (6.4±2.5) days. The abscess in pelvic-rectal space accounted for 55.0% (22/40) and the diameter of abscess was (8.2±3.5) cm. The differences in baseline data between two groups were not statistically significant (all P>0.05). Both groups successfully completed the operation. There was no significant difference in operative time between two groups (P>0.05). As compared to conventional drainage group, intraoperative blood loss in negative pressure irrigation and suction group was less [(12.1±5.5) ml vs. (18.3±4.4) ml, t=5.606, P<0.001], incision length was shorter [(2.3±0.8) cm vs. (7.6±1.7) cm, t=17.741, P<0.001], postoperative VAS pain scores at 1-, 3-, 7-, and 14-day after operation were lower [3.7±1.4 vs. 7.6±1.8, t=10.816, P<0.001; 3.0±1.3 vs. 6.8±1.6, t=11.657, P<0.001; 2.7±0.9 vs. 5.1±1.1, t=10.679, P<0.001; 1.2±0.3 vs. 1.6±0.4, t=5.060, P=0.019], the dressing change within 7 days after operation was less (3.5±1.2 vs. 12.6±2.7, t=19.478, P<0.001), postoperative healing time was shorter [(10.4±3.0) d vs. (13.5±3.8) d, t=4.049, P<0.001] and postoperative complication rate was lower [17.5% (7/40) vs. 2.5% (1/40), χ2=5.000, P=0.025]. During follow-up of 12 to 36 (24±5) months, the recurrence rate of perianal abscess within 1 year after operation and anal fistula formation rate in negative pressure irrigation and suction group were lower than those in conventional drainage group [5.0% (2/40) vs. 20.0% (8/40), χ2=4.114, P=0.042 and 2.5% (1/40) vs. 17.5% (7/40), χ2=5.000, P=0.025, respectirely]. The one-time cure rate of negative pressure irrigation and suction group and conventional drainage group was 92.5% (37/40) and 62.5%(25/40), respectirely (χ2=10.323, P=0.001). Conclusions: The application of the negative pressure irrigation and suction device in the treatment of high perianal abscess can improve the efficiency of one-time cure, reduce postoperative pain, accelerate healing time, decrease the morbidity of postoperative complication and the rates of abscess recurrence and anal fistula formation, indicating an improvement of the treatment.

ERCC polymorphisms and risk of osteosarcoma: a meta-analysis.

OBJECTIVE: The association between excision repair cross-complementation (ERCC) gene family (ERCC1 and ERCC2) and osteosarcoma risk was controversial. The aim of this study was to evaluate the association between ERCC1 or ERCC2 and osteosarcoma risk by systematic meta-analysis. MATERIALS AND METHODS: Relative studies were retrieved from electronic databases without language restriction. The last search was updated on March 2017. Quality assessment was analyzed by the Newcastle-Ottawa Scale (NOS) score, which was recommended by the Agency for Healthcare Research and Quality (AHRQ). Meta-analysis was conducted by R language package (R 3.12). RESULTS: This meta-analysis was performed based on 4 case-control studies that included 1208 cases and 2448 controls. The ERCC2-rs1799793 AA+AC > CC (OR=1.3428, 95% CI=1.0201; 1.7674) had an effect on the risk of osteosarcoma development, whereas, there were no significant associations among the other ERCC SNPs (ERCC1 rs3212986, ERCC1 rs11615, and ERCC2 rs13181) and osteosarcoma. CONCLUSIONS: The ERCC2 rs1799793 polymorphism is related to the high risk of osteosarcoma development.

["3-step" strategy of transperineal anastomotic urethroplasty for the simple pelvic fracture urethral distraction defect in male patients].

OBJECTIVE: To evaluate the clinical effect of "3-step" strategy of transperineal anastomotic urethroplasty for the simple pelvic fracture urethral distraction defect in male patients. METHODS: We retrospectively reviewed the clinical data of 162 male patients with simple traumatic posterior urethral stricture or stenosis admitted from January 2014 to October 2015. All had no complex complications, such as urethroperineal fistulas or urethrorectal fistulas. Before referral to Department of Urology, Beijing Jishuitan Hospital, 64 patients had undergone previous treatments: urethroplasty in 30 patients (18.5%), early urethral realignment in 17 patients (10.5%) and 17 patients (10.5%) who had undergone internal urethrotomy. The remaining 98 patients received the suprapubic cystostomy in the acute setting. All of them had received transperineal anastomotic urethroplasty with "3-step" strategy. Step 1, the bulbar urethra was circumferentially mobilized and tension-free anastomosis could be performed after the scar was completely incised and removed. Step 2, if after step 1 a tension-free anastomosis could not be achieved, were routed the distal urethra between the separated corporal bodies. Step 3, if the anastomosis still seemed to be under tension, we could perform pubectomy, partial or total removal, to get a better exposure of the apex of the prostate-membranous urethra. RESULTS: The mean age of the patients included in this study was 36.3 years (rangingfrom 16-74 years). The mean time between incidents and operation was 13.5 months (ranging from 3-124 months) and the mean length of stricture was 2.7 cm (ranging from 0.5-6.5 cm).The mean time of operation was 92 (45-240) min and the mean evaluated blood lose was 120 (60-800) mL. Three patients (1.9%) received blood transfusing during or after the operations. The numbers of the patients who completed step 1, step 2 and step 3 were 50(30.9%), 74(45.7%) and 38(23.5%), respectively. There were 4 (2.5%) patients who needed the combined transpubic and transperineal approach for tension-free anastomosis after removing an entire wedge of anterior pubis. The mean follow-up was 19.5 months and 18 patients' strictures recurred with manifestation of decreased stream of dysuria. The overall success rate was 88.9%(144/162). CONCLUSION: Based on the "3-step" strategy of transperineal anastomotic urethroplasty, patients with simple PFUDD can achieve a tension-free anastomosis. The present clinical data showed a successful rate of 88.9% (144/162).

Oncologic Outcomes of Post-Kidney Transplantation Superficial Urothelial Carcinoma.

PURPOSE: To analyze the oncologic effect of post-kidney transplantation (KT) immunosuppressive status for end-stage renal disease (ESRD) patients with superficial urothelial carcinoma. METHODS: From 2010 to 2015, there were 106 ESRD patients with superficial urinary bladder urothelial carcinoma (UB-UC) and 68 ESRD patients with superficial upper urinary tract urothelial carcinoma (UT-UC) in a single institution. Oncologic outcomes including bladder cancer recurrences and systemic disease recurrences within 5 years were compared between patients with and without KT. Superficial urothelial carcinoma was defined as Tis/Ta/T1 without nodal disease or distant metastasis. All the patients underwent standard transurethral resection of bladder tumor (TURBT) for superficial UB-UC and radical nephroureterectomy for superficial UT-UC. RESULTS: Patients with KT were younger according to our observation. Female predominance was noted in patients with UT-UC and post-KT UB-UC. Pathological stages were distributed similarly in UB-UC and UT-UC groups whether they underwent KT or not. More bladder cancer recurrences within 5 years were found in ESRD patients with KT after TURBT for superficial UB-UC compared with those without KT (77.7% vs 38%, P = .032). However, systemic disease recurrences were similar in the 2 groups (11% vs 1%, P = .163). For superficial UT-UC, there were no differences in bladder cancer recurrences and systemic disease recurrences in the 2 groups (25% vs 39%, P = .513 and 16% vs 3.5%, P = .141). CONCLUSION: For post-KT superficial urothelial carcinoma, radical surgery seems to result in better oncologic outcome. However, radical cystectomy is not a standard treatment choice for superficial bladder cancer. A higher incidence of bladder cancer recurrence after TURBT was found in ESRD patients with KT than those without KT.

Kirigami-based Elastic Metamaterials with Anisotropic Mass Density for Subwavelength Flexural Wave Control.

A novel design of an elastic metamaterial with anisotropic mass density is proposed to manipulate flexural waves at a subwavelength scale. The three-dimensional metamaterial is inspired by kirigami, which can be easily manufactured by cutting and folding a thin metallic plate. By attaching the resonant kirigami structures periodically on the top of a host plate, a metamaterial plate can be constructed without any perforation that degrades the strength of the pristine plate. An analytical model is developed to understand the working mechanism of the proposed elastic metamaterial and the dispersion curves are calculated by using an extended plane wave expansion method. As a result, we verify an anisotropic effective mass density stemming from the coupling between the local resonance of the kirigami cells and the global flexural wave propagations in the host plate. Finally, numerical simulations on the directional flexural wave propagation in a two-dimensional array of kirigami metamaterial as well as super-resolution imaging through an elastic hyperlens are conducted to demonstrate the subwavelength-scale flexural wave control abilities. The proposed kirigami-based metamaterial has the advantages of no-perforation design and subwavelength flexural wave manipulation capability, which can be highly useful for engineering applications including non-destructive evaluations and structural health monitoring.

Non-reciprocal wave propagation in modulated elastic metamaterials.

Time-reversal symmetry for elastic wave propagation breaks down in a resonant mass-in-mass lattice whose inner-stiffness is weakly modulated in space and in time in a wave-like fashion. Specifically, one-way wave transmission, conversion and amplification as well as unidirectional wave blocking are demonstrated analytically through an asymptotic analysis based on coupled mode theory and numerically thanks to a series of simulations in harmonic and transient regimes. High-amplitude modulations are then explored in the homogenization limit where a non-standard effective mass operator is recovered and shown to take negative values over unusually large frequency bands. These modulated metamaterials, which exhibit either non-reciprocal behaviours or non-standard effective mass operators, offer promise for applications in the field of elastic wave control in general and in one-way conversion/amplification in particular.

Wave propagation and absorption of sandwich beams containing interior dissipative multi-resonators.

In this study, a sandwich beam with periodic multiple dissipative resonators in the sandwich core material is investigated for broadband wave mitigation and/or absorption. An analytical approach based on the transfer matrix method and Bloch theorem is developed for both infinite and finite sandwich structures. Wave attenuation constants are theoretically obtained to examine the effects of various system parameters on the position, width and wave attenuation performance of the band gaps. The wave absorption coefficient of the sandwich beam is quantitatively studied to distinguish wave attenuation mechanisms caused by reflection and absorption. It is numerically demonstrated that a transient blast-induced elastic wave with broadband frequencies can be almost completely mitigated or absorbed at a subwavelength scale. The results of this study could be used for developing new multifunctional composite materials to suppress impact-induced and/or blast-induced elastic waves which may cause severe local damage to engineering structures.

Enhanced flexural wave sensing by adaptive gradient-index metamaterials.

Increasing sensitivity and signal to noise ratios of conventional wave sensors is an interesting topic in structural health monitoring, medical imaging, aerospace and nuclear instrumentation. Here, we report the concept of a gradient piezoelectric self-sensing system by integrating shunting circuitry into conventional sensors. By tuning circuit elements properly, both the quality and quantity of the flexural wave measurement data can be significantly increased for new adaptive sensing applications. Through analytical, numerical and experimental studies, we demonstrate that a metamaterial-based sensing system (MBSS) with gradient bending stiffness can be designed by connecting gradient negative capacitance circuits to an array of piezoelectric patches (sensors). Furthermore, we demonstrate that the proposed system can achieve more than two orders of magnitude amplification of flexural wave signals to overcome the detection limit. This research encompasses fundamental advancements in the MBSS with improved performance and functionalities, and will yield significant advances for a range of applications.

A single-phase elastic hyperbolic metamaterial with anisotropic mass density.

Wave propagation can be manipulated at a deep subwavelength scale through the locally resonant metamaterial that possesses unusual effective material properties. Hyperlens due to metamaterial's anomalous anisotropy can lead to superior-resolution imaging. In this paper, a single-phase elastic metamaterial with strongly anisotropic effective mass density has been designed. The proposed metamaterial utilizes the independently adjustable locally resonant motions of the subwavelength-scale microstructures along the two principal directions. High anisotropy in the effective mass densities obtained by the numerical-based effective medium theory can be found and even have opposite signs. For practical applications, shunted piezoelectric elements are introduced into the microstructure to tailor the effective mass density in a broad frequency range. Finally, to validate the design, an elastic hyperlens made of the single-phase hyperbolic metamaterial is proposed with subwavelength longitudinal wave imaging illustrated numerically. The proposed single-phase hyperbolic metamaterial has many promising applications for high resolution damage imaging in nondestructive evaluation and structural health monitoring.

Genetic mechanism associated with congenital cytomegalovirus infection and analysis of effects of the infection on pregnancy outcome.

We aimed to compare the diagnostic value of various detection methods for cytomegalovirus (CMV) infection, to investigate the genetic mechanism associated with CMV infection in pregnant women, and to analyze the risk of sequelae development in fetuses with CMV infection. A total of 300 participants who had the same immunosuppressive regimen and received preemptive therapy for CMV infection were prospectively enrolled in this study; they included 289 vaccine trial participants. The gB-absorbed CMV IgG assay was performed for each vaccine trial participant. The healthy women were divided into 2 groups, and amniotic fluids were collected from them at 15-18 weeks of gestation to test for CMV seropositivity before conception by using IgM specific antibodies, CMV-DNA, and IgG analysis. In 104 cases, cord blood sera and urine specimens were also collected from the infants and examined. The sensitivity and specificity of immediate-early messenger RNA and pp67 (late) messenger RNA detection by the nucleic acid sequence-based amplification technique was comparable to those of virus isolation and PCR. Furthermore, an association between single nucleotide polymorphisms in the TLR-2 gene and congenital CMV infection was observed and confirmed. Moreover, CMV infection during early pregnancy has been shown to have a much more severe effect on the pregnancy outcome compared to infection during later stages of pregnancy.