SK-Unet++: An improved Unet++ network with adaptive receptive fields for automatic segmentation of ultrasound thyroid nodule images.

BACKGROUND: The quality of segmentation of thyroid nodules in ultrasound images is a crucial factor in preventing the cancerization of thyroid nodules. However, the existing standards for the ultrasound imaging of cancerous nodules have limitations, and changes of the echo pattern of thyroid nodules pose challenges in accurately segmenting nodules, which can affect the diagnostic results of medical professionals. PURPOSE: The aim of this study is to address the challenges related to segmentation accuracy due to noise, low contrast, morphological scale variations, and blurred edges of thyroid nodules in ultrasound images and improve the accuracy of ultrasound-based thyroid nodule segmentation, thereby aiding the clinical diagnosis of thyroid nodules. METHOD: In this study, the dataset of thyroid ultrasound images was obtained from Hunan Provincial People's Hospital, consisting of a total of 3572 samples used for the training, validation, and testing of this model at a ratio of 8:1:1. A novel SK-Unet++ network was used to enhance the segmentation accuracy of thyroid nodules. SK-Unet++ is a novel deep learning architecture that adds the adaptive receptive fields based on the selective kernel (SK) attention mechanisms into the Unet++ network. The convolution blocks of the original UNet++ encoder part were replaced with finer SK convolution blocks in SK-Unet++. First, multiple skip connections were incorporated so that SK-Unet++ can make information from previous layers of the neural network to bypass certain layers and directly propagate to subsequent layers. The feature maps of the corresponding locations were fused on the channel, resulting in enhanced segmentation accuracy. Second, we added the adaptive receptive fields. The adaptive receptive fields were used to capture multiscale spatial features better by dynamically adjusting its receptive field. The assessment metrics contained dice similarity coefficient (Dsc), accuracy (Acc), precision (Pre), recall (Re), and Hausdorff distance, and all comparison experiments used the paired t-tests to assess whether statistically significant performance differences existed (p < 0.05). And to address the multi-comparison problem, we performed the false discovery rate (FDR) correction after the test. RESULTS: The segmentation model had an Acc of 80.6%, Dsc of 84.7%, Pre of 77.5%, Re of 71.7%, and an average Hausdorff distance of 15.80 mm. Ablation experimental results demonstrated that each module in the network could contribute to the improved performance (p < 0.05) and determined the best combination of parameters. A comparison with other state-of-the-art methods showed that SK-Unet++ significantly outperformed them in terms of segmentation performance (p < 0.05), with a more accurate segmentation contour. Additionally, the adaptive weight changes of the SK module were monitored during the training process, and the resulting change curves demonstrated their convergence. CONCLUSION: Our proposed method demonstrates favorable performance in the segmentation of ultrasound images of thyroid nodules. Results confirmed that SK-Unet++ is a feasible and effective method for the automatic segmentation of thyroid nodules in ultrasound images. The high accuracy achieved by our method can facilitate efficient screening of patients with thyroid nodules, ultimately reducing the workload of clinicians and radiologists.

Multi-UAV Cooperative Trajectory Planning Based on the Modified Cheetah Optimization Algorithm.

The capacity for autonomous functionality serves as the fundamental ability and driving force for the cross-generational upgrading of unmanned aerial vehicles (UAVs). With the disruptive transformation of artificial intelligence technology, autonomous trajectory planning based on intelligent algorithms has emerged as a key technique for enhancing UAVs' capacity for autonomous behavior, thus holding significant research value. To address the challenges of UAV trajectory planning in complex 3D environments, this paper proposes a multi-UAV cooperative trajectory-planning method based on a Modified Cheetah Optimization (MCO) algorithm. Firstly, a spatiotemporal cooperative trajectory planning model is established, incorporating UAV-cooperative constraints and performance constraints. Evaluation criteria, including fuel consumption, altitude, and threat distribution field cost functions, are introduced. Then, based on its parent Cheetah Optimization (CO) algorithm, the MCO algorithm incorporates a logistic chaotic mapping strategy and an adaptive search agent strategy, thereby improving the home-returning mechanism. Finally, extensive simulation experiments are conducted using a considerably large test dataset containing functions with the following four characteristics: unimodal, multimodal, separable, and inseparable. Meanwhile, a strategy for dimensionality reduction searching is employed to solve the problem of autonomous trajectory planning in real-world scenarios. The results of a conducted simulation demonstrate that the MCO algorithm outperforms several other related algorithms, showcasing smaller trajectory costs, a faster convergence speed, and stabler performance. The proposed algorithm exhibits a certain degree of correctness, effectiveness, and advancement in solving the problem of multi-UAV cooperative trajectory planning.

Stereoselective synthesis of α-glucosides with glucosyl (Z)-Ynenoates as donors.

A SPhosAuNTf2-promoted DMF-modulated glycosylation approach with glycosyl (Z)-ynenoates as donors was developed for highly α-selective synthesis of various linkage types of α-glucans. The substituent groups were also found to play a significant role in the α-selective glucosylation reactions. The glycosylation approach was effectively applied to the stereospecific synthesis of the α-1,6-linked triglucoside.

Evaluation of high-dielectric pads for macaque brain imaging at 7 T.

A non-human primate is a valuable model for investigating the structure and function of the brain. Different from the human brain imaging using radio frequency (RF) head coils, in the present study, on a human whole-body 7 T magnetic resonance imaging system, we used an RF knee coil for monkey brain imaging in vivo due to the smaller size of the macaque's brain compared to that of a human, and particularly, high-dielectric pads were also utilized in order to improve brain imaging performance. Our experimental results suggest that high-dielectric pads can effectively enhance the B1 field strength and receive sensitivity, leading to a higher flip-angle magnitude, an image signal-to-noise ratio, and tissue contrast, and in the meantime, we did not observe elevated receive array element coupling and receive noise amplification nor apparent magnetic susceptibility-induced artifact or distortion, showing that the pads do not introduce adverse RF interferences in macaque brain imaging at 7 T.

Prevention of postoperative adhesion reformation by intermittent intrauterine balloon therapy: a randomised controlled trial.

OBJECTIVE: To compare the efficacy of intermittent intrauterine balloon dilatation versus standard care in the prevention of adhesion reformation. DESIGN: Single-blind randomised controlled trial. SETTING: Hysteroscopic Centre of a tertiary University Hospital. POPULATION: Two hundred patients with moderate to severe (European Society for Gynaecological Endoscopy Grade ≥II) intrauterine adhesions who underwent hysteroscopic adhesiolysis. METHODS: All participants were randomised to a balloon group or a control group postoperatively. The balloon group received intrauterine balloon dilatation therapy at 2 weeks and 6 weeks after surgery, whereas the control group did not. All patients underwent follow-up hysteroscopy at 4 and 8 weeks postoperatively. MAIN OUTCOME MEASURES: The adhesion reformation rate and the Pictorial Blood Loss Assessment Chart scores were analysed. RESULTS: A total of 191 patients successfully completed the study protocol (94 cases for the balloon group and 97 cases for the control group). According to hysteroscopic evaluation at the 8th week, the overall adhesion reformation rate was significantly lower in patients in the balloon group than patients in the control group (20.2% versus 40.2%, respectively; P < 0.05). There was also a significant increase in menstruation flow, as assessed by the Pictorial Blood Loss Assessment Chart score (30 versus 9, respectively; P < 0.001). CONCLUSIONS: Postoperative intermittent intrauterine balloon dilatation therapy can significantly reduce postoperative adhesion reformation and significantly increase menstruation flow. TWEETABLE ABSTRACT: RCT: Postoperative intermittent intrauterine balloon therapy can prevent adhesion reformation after hysteroscopic adhesiolysis.

Management of false passage created during hysteroscopic adhesiolysis for Asherman's syndrome.

False passage in the uterus, if unrecognised, will almost certainly lead to perforation of the uterus and associated complications. We present our experience of the management of a false passage encountered during hysteroscopic surgery for the treatment of severe Asherman's syndrome. Five women with severe Asherman's syndrome resulting in complete obliteration of the uterine cavity and a false passage created during hysteroscopy were included in our study. A subsequent hysteroscopy was performed under ultrasound guidance with preoperative oestrogen therapy to increase endometrial thickness. In all 5 cases, the uterine cavity was successfully entered during the repeat hysteroscopy, which enabled the adhesiolysis procedure to be completed. There was satisfactory improvement in menstrual pattern and significant reduction in intrauterine the adhesion score. Two of the three patients who wished to conceive did become pregnant. The early recognition of a false passage inadvertently created during hysteroscopy is crucial in preventing further damage to the uterus.

The expression of cyclooxygenase-2 and vascular endothelial growth factor in the endometrium during the peri-implantation period in women with and without polyps.

OBJECTIVE: This prospective study was designed to determine whether the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in the endometrial tissue obtained from the peri-implantation period of women with endometrial polyp (EP) differs from that of control subjects without a polyp. METHODS: Endometrial samples were collected from 30 patients with EP and 30 control subjects without EP, in the mid-secretory phase. The expression of COX-2 and VEGF in the endometrium was examined with the use of immunohistochemistry. RESULTS: COX-2 and VEGF were predominantly expressed in endometrial glands. The expression of COX-2 and VEGF in the endometrium obtained from women with EP was lower than that of control subjects. CONCLUSION: The reduced expression of COX-2 and VEGF in the endometrium of women with EP may account for the association between EP and infertility.

Preclinical characterization of the antiviral activity of SCH 900518 (narlaprevir), a novel mechanism-based inhibitor of hepatitis C virus NS3 protease.

Small-molecule hepatitis C virus (HCV) NS3 protease inhibitors such as boceprevir (SCH 503034) have been shown to have antiviral activity when they are used as monotherapy and in combination with pegylated alpha interferon and ribavirin in clinical trials. Improvements in inhibitor potency and pharmacokinetic properties offer opportunities to increase drug exposure and to further increase the sustained virological response. Exploration of the structure-activity relationships of ketoamide inhibitors related to boceprevir has led to the discovery of SCH 900518, a novel ketoamide protease inhibitor which forms a reversible covalent bond with the active-site serine. It has an overall inhibition constant (K*(i)) of 7 nM and a dissociation half-life of 1 to 2 h. SCH 900518 inhibited replicon RNA at a 90% effective concentration (EC(90)) of 40 nM. In biochemical assays, SCH 900518 was active against proteases of genotypes 1 to 3. A 2-week treatment with 5x EC(90) of the inhibitor reduced the replicon RNA level by 3 log units. Selection of replicon cells with SCH 900518 resulted in the outgrowth of several resistant mutants (with the T54A/S and A156S/T/V mutations). Cross-resistance studies demonstrated that the majority of mutations for resistance to boceprevir and telaprevir caused similar fold losses of activity against all three inhibitors; however, SCH 900518 retained more activity against these mutants due to its higher intrinsic potency. Combination treatment with alpha interferon enhanced the inhibition of replicon RNA and suppressed the emergence of resistant replicon colonies, supporting the use of SCH 900518-pegylated alpha interferon combination therapy in the clinic. In summary, the results of the preclinical characterization of the antiviral activity of SCH 900518 support its evaluation in clinical studies.

A comparison of oestrogen receptor and progesterone receptor expression in endometrial polyps and endometrium of premenopausal women.

SUMMARY: Polyps from the endometrium is a common cause of abnormal uterine bleeding and sometimes cause infertility and pelvic pain. The objective of this study was to measure the expression of hormone receptors (oestrogen receptor and progesterone receptor) in endometrial polyps and compare the results to surrounding endometrial tissue. This prospective study recruited 53 women prior to menopause. The study showed that the expression of oestrogen receptor was higher whereas the expression of progesterone receptor was lower than that of adjacent endometrial tissue. The results suggest that abnormal expression of hormone receptor contribute to endometrial polyps formation.

SCH 503034, a mechanism-based inhibitor of hepatitis C virus NS3 protease, suppresses polyprotein maturation and enhances the antiviral activity of alpha interferon in replicon cells.

Cleavage of the hepatitis C virus (HCV) polyprotein by the viral NS3 protease releases functional viral proteins essential for viral replication. Recent studies by Foy and coworkers strongly suggest that NS3-mediated cleavage of host factors may abrogate cellular response to alpha interferon (IFN-alpha) (E. Foy, K. Li, R. Sumpter, Jr., Y.-M. Loo, C. L. Johnson, C. Wang, P. M. Fish, M. Yoneyama, T. Fujita, S. M. Lemon, and M. Gale, Jr., Proc. Natl. Acad. Sci. USA 102:2986-2991, 2005, and E. Foy, K. Li, C. Wang, R. Sumpter, Jr., M. Ikeda, S. M. Lemon, and M. Gale, Jr., Science 300:1145-1148, 2003). Blockage of NS3 protease activity therefore is expected to inhibit HCV replication by both direct suppression of viral protein production as well as by restoring host responsiveness to IFN. Using structure-assisted design, a ketoamide inhibitor, SCH 503034, was generated which demonstrated potent (overall inhibition constant, 14 nM) time-dependent inhibition of the NS3 protease in cell-free enzyme assays as well as robust in vitro activity in the HCV replicon system, as monitored by immunofluorescence and real-time PCR analysis. Continuous exposure of replicon-bearing cell lines to six times the 90% effective concentration of SCH 503034 for 15 days resulted in a greater than 4-log reduction in replicon RNA. The combination of SCH 503034 with IFN was more effective in suppressing replicon synthesis than either compound alone, supporting the suggestion of Foy and coworkers that combinations of IFN with protease inhibitors would lead to enhanced therapeutic efficacy.

Characterization of monoclonal antibodies that specifically recognize the palm subdomain of hepatitis C virus nonstructural protein 5B polymerase.

The nonstructural protein 5B (NS5B) of hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) which plays an essential role in viral RNA replication. Antibodies that specifically recognize NS5B will have utilities in monitoring NS5B production and subcellular localization, as well as in structure-function studies. In this report, three mouse monoclonal antibodies (mAbs), 16A9C9, 16D9A4 and 20A12C7, against a recombinant NS5B protein (genotype 1a, H-77 strain) were produced. These mAbs specifically recognize HCV NS5B, but not RdRps of polivirus (PV), bovine viral diarrhea virus (BVDV) or GB virus B (GBV-B). The mAbs can readily detect NS5B in cellular lysates of human osteosarcoma Saos2 cells constitutively expressing the nonstructural region of HCV (NS3-NS4A-NS4B-NS5A-NS5B). NS5B proteins of different HCV genotypes/subtypes (1a, 1b, 2a, 2c, 5a) showed varied affinity for these mAbs. Interestingly, the epitopes for the mAbs were mapped to the palm subdomain (amino acid 188-370) of the HCV RdRp as determined by immunoblotting analysis of a panel of HCV/GBV-B chimeric NS5B proteins. The binding site was mapped between amino acid 231 and 267 of NS5B for 16A9C9, and between 282 and 372 for 16D9A4 and 20A12C7. Furthermore, these mAbs showed no inhibitory effect on the NS5B polymerase activity in vitro.

[Effect of mifepristone on the expression of tumor necrosis factor-alpha and transforming growth factor-beta in decidua of early pregnancy].

OBJECTIVE: To investigate the effect of mifepristone on the expression of tumor necrosis factor-alpha(TNF-alpha) and transforming growth factor-beta(TGF-beta) in decidua of early pregnancy. METHODS: Thirty artificial abortion women as control and thirty drug abortion women were enrolled for study. The expressions of TNF-alpha and TGF-beta in decidua were measured with immunohistochemical method. RESULTS: There was no significant difference of TNF-alpha positive expression rates between drug abortion group (73.33%) and artificial abortion group (70.00%, P > 0.05). TGF-beta expression rate of drug abortion group was similar to that of artificial abortion group. The highly-positive (++ and +++) TNF-alpha expression rate in drug abortion group was significantly higher than that in artificial abortion group (P < 0.05). TGF-beta expression degree in decidua of drug abortion group was significantly lower than that of artificial abortion group (P < 0.05). The ratio of TNF-alpha/TGF-beta in drug abortion group is higher than that in artificial abortion group. CONCLUSION: TGF-beta has great effect on regulating the embryo development of early pregnancy. The change of TNF-alpha may be the reason of abortion. Mifepristone may interfere with embryo growth by inhibiting the activity of TGF-beta or by stimulating the secretion of TNF-alpha.

Incidence of deep venous thrombosis after gynaecological laparoscopy.

OBJECTIVE: To evaluate the incidence of deep venous thrombosis (DVT) after gynaecological laparoscopy. METHODS: The incidence of DVT was studied in 72 consecutive patients who underwent gynaecological laparoscopy in the Liverpool Health Service between May and September 1997. B-mode ultrasound supplemented by Doppler was used to examine venous patency and intraluminal echoes to diagnose DVT. Sixty-one patients who had pneumoperitoneum less than 60 minutes were classified a minor procedure and 11 who had pneumoperitoneum more than 60 minutes were classified as major procedure. Two Doppler ultrasound scans were planned for every patient. The first one was done within 24 hours and the second was performed on day 7 post-surgery. All 72 patients had the first scan and 40 out of 61 in the minor procedure group and 9 out of 11 in the major procedure had the second scan. Twenty-three patients who did not come for the second scan were followed up by phone. RESULTS: No DVT was found in our study. CONCLUSION: This study confirms an impression that gynaecological laparoscopic procedure has a very low incidence of DVT. If it occurs, the diagnosis and treatment must be made as soon as possible so that the fatal complications such as pulmonary embolus can be avoided.

[Severe complications of hysteroscopic surgeries: an analysis of 35 cases].

OBJECTIVE: To investigate the methods of earlier diagnosis, treatment and precautions on the severe complications of hysteroscopic procedures. METHODS: There were 12 921 cases of diagnostic hysteroscopy and 2 221 cases of operative hysteroscopy were performed. For diagnostic hysteroscopy B ultrasonography were scaned meanwhile and fluid media were used to distend the uterus. For operation hysteroscopy B ultrasonography or laparoscopy was used for monitoring. RESULTS: Thirty five cases of severe complications encountered. There were 9 cases of severe intraoperative bleeding. Foley catheter inserting, bleeding spots coagulating, uterine cavity tampon or hysterectomy were used to stop intraoperative and postoperative bleeding successfully. Eleven cases of uterine perforation were treated by conservativetherapy, laparoscopy or hysterectomy. An air embolism happened on hysteroscopic examination was survived with aggressive rescue. There were 4 cases of postoperative infection that had history of pelvic inflammatory disease and cured by antibiotics. Diuretic agent and saline infusion were used to treat 5 cases of transurethral resection of prostate (TURP) syndrome effectively. For 4 cases of post-ablationsterilization syndrome (PASS) dilating the cervix canal and expelling the hematometra, transcervical resection of adhesions or hysterectomy were managed effectively. One case of endometrial adenocarcinoma stage I a was diagnosed 8 years after transcervical resection of endometrium (TCRE) & transcervical resection of polyp (TCRP), and radical hysterectomy plus selective pelvic lymphadenectomy was performed. CONCLUSIONS: Foley catheter insertion is a simple and efficient method to stop uterine bleeding. Uterine adhesion is a high risk factor of uterine perforation. Monitoring by B ultrasonography or laparoscopy could not prevent uterine perforation. Prevention was essential for air embolism. Control the pressure of irrigating flow and operating time can reduce the incidence of TURP syndrome. To intensify follow-up is the best method to detect PASS and uterine adenocarcinoma.

[Study on the electrothermal tissue effects during transcervical resection of endometrium].

OBJECTIVE: To investigate the tissue electrothermal effects and to seek the appropriate setting of operative wattage during transcervical resection of endometrium (TCRE). METHODS: The power setting were 60 W, 80 W, 100 W for cutting and 30 W, 60 W, 80 W, 100 W for coagulation when performing endometrial resection in vitro or in vivo with operating time 3-5 seconds or 6-8 seconds respectively. After operation the uterine specimens were stained by hemaloxylin-eosin, and respiratory enzyme dehydronicotinamide adenine dinucleotide phosphate diaphorase methods for evaluating the tissue damage. RESULTS: (1) The depth of endometrial damage under cutting was considerably less severe than those under coagulation with the same power setting. (2) When the power of cutting and coagulation were 80 W, 100 W and 30 W, 60 W respectively and operating time prolonged more than 5 seconds, the thermal damage covered endometrium and 2-3 mm of myometrium in depth. (3) At such wattage and operating time the deepest destruction was only 16.27% of uterine wall. CONCLUSION: (1) There is significant difference in the depth of thermal damage between cutting and coagulation during hysteros copic surgery. (2) The appropriate power setting should be 80-100 W for cutting and 30-60 W for coagulation.

Uptake of N,N-dimethyl-2-phenylethylene HCl into acini cells removed from rabbit lacrimal glands.

Acini cells were obtained from the lacrimal gland of the white New Zealand rabbit. Following isolation and purification, the cells were used to study the uptake of N,N'-dimethyl-2-phenylethylamine HCl (AF2975), which was found to be sodium- and proton-independent, but energy-dependent. Uptake was mainly accomplished via a carrier-mediated transport system for which a Km of 8.72+/-0.96 mM, a Vmax of 602.6+/-41.3 nmol/mg of protein/min, and an exponential coefficient of 2.55+/-0.46 were obtained following a least squares nonlinear fit to the Hill equation. With the addition of the metabolic inhibitors, sodium azide or 2,4-dinitrophenol, the initial uptake rates were reduced from the control experiments by 35.7% and 26.2%, respectively.

Combination of hysteroscopy and laparoscopy in gynecologic operation: an analysis of 65 cases.

OBJECTIVE: To introduce the procedures, preliminary experience, and advantages of operation using combination of hysteroscopy and laparoscopy. METHODS: Sixty-five women underwent transcervical resection of endometrium (11), myoma (38), polyp (2), septa (9), adhesion (1) or foreign body (4). All had the indications for simultaneous laparoscopic monitoring and operation. They were first diagnosed laparoscopically to decide the type of laparoscopic operation. Then they were treated hysteroscopically and finally received laparoscopic operation. RESULTS: Laparoscopic examinations confirmed the original diagnoses, revealed the causes of pelvic pain in 8 patients, and detected ovarian cyst, endometriosis, and pelvic adhesion in 5. Two cases of uterine perforation were found by laparoscopic monitoring. Thirty laparoscopic operations included removal or puncture of ovarian cyst, lysis of adhesion, coagulation of endometriosis, Rubin's test, and partial salpingectomy. The postoperative course was smooth and the operative result was satisfactory. CONCLUSIONS: Operations using combination of hysteroscopy and laparoscopy are safe and effective. They also reduce the pain, and save the time and money of patients. Laparoscopic monitoring may detect uterine perforation in time.