Ultrasensitive Photoelectrochemical Biosensor for Dual-miRNAs Detection Based on Molecular Logic Gates and Methylene Blue Sensitized ZnO@CdS@Au Nanorods.

The occurrence of cancer is often closely related to multiple tumor markers, so it is important to develop multitarget detection methods. By the proper design of the input signals and logical operations of DNA logic gates, detection and diagnosis of cancer at different stages can be achieved. For example, in the early stages, specific input signals can be designed to correspond to early specific tumor markers, thereby achieving early cancer detection. In the late stage, logic gates for multitarget detection can be designed to simultaneously detect multiple biomarkers to improve diagnostic accuracy and comprehensiveness. In this work, we constructed a dual-target-triggered DNA logic gate for anchoring DNA tetrahedra, where methylene blue was embedded in the DNA tetrahedra to sensitize ZnO@CdS@Au, achieving ultrasensitive detection of the target substance. We tested the response of AND and OR logic gates to the platform. For AND logic gates, the sensing platform only responds when both miRNAs are present. In the concentration range of 10 aM to 10 nM, the photoelectric signal gradually increases with an increase of the target concentration. Subsequently, we used OR logic gates for miRNA detection. Even if only one target exists, the sensing platform exhibits excellent performance. Similarly, within the concentration range of 10 aM to 10 nM, the photoelectric signal gradually increases with an increase of the target concentration. The minimum detection limit is 1.10 aM. Whether it is the need to detect multiple targets simultaneously or only one of them, we can achieve it by selecting the appropriate logic gate. This strategy holds promising application prospects in fields such as biosensing, medical diagnosis, and environmental monitoring.

Experience and levels of satisfaction with the levonorgestrel-releasing intrauterine system in China: a prospective multicenter survey.

BACKGROUND: Although surveys conducted in Western countries have shown that the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena(®)) is well accepted by European women, its acceptance by Chinese women is not yet clearly known. The purpose of this study was to analyze the experiences and levels of satisfaction with Mirena among Chinese women living in 12 different cities. METHODS: In total, 1,021 women who attended 21 medical centers for insertion of Mirena were invited to complete a questionnaire regarding their contraceptive decision at baseline (preinsertion), and two further questionnaires on their experience and satisfaction with Mirena at 3-6 months and 1 year after insertion. RESULTS: At baseline, 36% of women self-reported heavy or very heavy menstrual bleeding, while 41% reported normal bleeding. The majority of women (98%) were satisfied with the preinsertion counseling, during which contraceptive reliability was identified as the most important reason for considering Mirena. Continuation rates for Mirena were 99% at 3-6 months and 93% at 12 months after insertion, and most women (92% and 93%, respectively) had less bleeding at these times. The percentage of women who rated Mirena as better than their previous contraceptive method was 63%. Overall, around 90% of respondents were very satisfied or rather satisfied with Mirena, and 64% stated that they would recommend it to their friends. CONCLUSION: These data suggest that continuation and satisfaction rates with Mirena were very high, and that the device is well accepted by Chinese women.

[A multicenter prospective randomized open comparative study on the treatment of ovulatory menorrhagia with tranexamic acid and norethisterone in China].

OBJECTIVE: To compare the efficacy and safety of tranexamic acid (TA) and norethisterone (NET) for the treatment of patients with ovulatory menorrhagia in China. METHODS: One hundred and thirty one patients with proven ovulatory menorrhagia from gynecologic clinics of 5 teaching hospitals located in 4 different cities in China were enrolled during Jul 2004 to Dec 2006. Among them 128 completed the study. Patients were randomly divided into two therapeutic regimen groups: TA 1 g thrice daily during menstrual cycle days (D) 1-5, 69 cases; or NET 5 mg twice daily on D19-26, 59 cases. The drugs were administered for 2 consecutive cycles, then withdrawn and patients were followed-up for 1 more cycle. Data on menstrual blood loss [estimated by pictorial blood assessment chart (PBAC)], length of menstrual periods, quality of life (QOL) evaluated by a 6 item health-related questionnaire were collected before, during each cycle and were compared. RESULTS: Both treatments led to significant decreases of mean PBAC scores and shorter duration of menstrual periods, and improved the QOL ranking during the two treatment cycles. The mean percentages of PBAC decrements in the TA first and second cycles were significantly greater than those in the NET corresponding cycles(35% vs 17% , P = 0.004; 44% vs 34%, P = 0.04 respectively). The success rate of TA second cycle was higher than that of the NET second cycle (41% vs 24%, P = 0.04). Improvement of QOL ranking in the TA first cycle was also significantly better than those in the NET first cycle (P = 0.03). The percentage of patients with at least 1 adverse event in TA group (19%) was significantly lower than that in NET group (35%, P = 0.04). Patients' willingness to continue the treatment in the TA second and follow-up cycles (94%, 79% respectively) were significantly higher than those in the corresponding cycles of NET groups (79%, 59% respectively; P = 0.01, P = 0.02). CONCLUSION: The regimen of TA 3 g daily during menstrual days 1-5 is a more effective and tolerable treatment than luteal phase norethisterone for patients with ovulatory menorrhagia.

[Construction of eukaryotic expression recombinant plasmid of trichomonas vaginalis ferredoxin gene].

Total DNA was extracted from T. vaginalis with Chelex-100 method and used as templates for PCR. The ferredoxin gene was directionally cloned into plasmid pMD-18T vector and subcloned into eukaryotic expression vector pcDNA3. 1 (+). The transformants were screened and identified by PCR and restriction analysis. The size of amplified ferredoxin gene was 306bp and the DNA sequence of cloned gene was same with that published.

[Cloning and sequence analysis of Trichomonas vaginalis ferredoxin gene].

OBJECTIVE: To construct a recombinant plasmid containing ferredoxin gene of Trichomonas vaginalis. METHODS: Total DNA was extracted from Trichomonas vaginalis with Chelex-100 method and used as templates for PCR. Primers were designed based on the published sequence of the ferredoxin gene and used to amplify the Trichomonas vaginalis gene using PCR method. The ferredoxin gene obtained by PCR technique was directionally cloned into plasmid pMD-18T simple vector. The constructed recombinant plasmid was transferred into E. coli JM109. The transformants were screened and identified by PCR and restriction analysis. The DNA sequence of the gene was determined by Sanger's method. RESULTS: The size of amplified ferredoxin gene was 306bp. The correct recombinant plasmid was isolated and confirmed by PCR and restriction analysis. The DNA sequence of cloned gene was the same as the published sequence. CONCLUSION: The ferredoxin gene was successfully amplified and cloned into plasmid pMD-18T simple vector. The cloned ferredoxin gene could be used to produce recombinant protein and for study of its function.