Phasing analysis on DRO with impulsive maneuver

The cis-lunar periodic orbit exhibits some unique dynamic characteristics. Among them is the distant retrograde orbit, which has long-term stability and is one of the ideal candidate deployment orbits for cis-lunar space stations and deep-space exploration transfer stations. Orbiting, rendezvous, and docking are among the flight operations involved in space station on-orbit construction, material supply, spacecraft monitoring, and other tasks. Suitable initial conditions can be created for these operations by shortening the relative distance between spacecraft through phasing. In this study, the characteristics of a two-impulse phasing orbit on a distant retrograde orbit (DRO) are summarized, and its phasing ability is globally analyzed. Based on these analyses, a phasing optimization problem was presented and solved. Using DRO’s dynamic characteristics, a DRO multi-impulse phasing rolling solution method is presented. For accuracy purposes, the orbit determination error is also considered in this method. The simulation analysis was performed using the circular restricted three-body problem (CR3BP) dynamic model and the ephemeris model. Compared with the results of two-impulse phasing, this method reduces the offset of the end position of the DRO phasing orbit from hundreds to tens of kilometers. This result satisfies the relative distance requirements for subsequent spacecraft operations. The total pulse requirement of this phasing method for the two models was within a reasonable and feasible range

HPV Infection and EGFR Activation/Alteration in HIV-Infected East African Patients with Conjunctival Carcinoma

Background There has been substantial growth in the numbers of patients with conjunctival squamous cell carcinoma infected with HIV in East Africa. The natural history of the conjunctival squamous cell carcinoma appears to be unique in this region of the world, but the etiologic mechanism unclear and therapeutic options limited. This research was carried out to determine if conjunctival squamous cell carcinoma harbors human papillomavirus DNA and is associated with activation of the EGFR signaling pathway. Positive findings would identify etiologic causes and provide clinical guidance to improve treatment. Methods/Findings Expression of p-MAPK/MAPK, p-Akt/Akt and p-EGFR/EGFR in cell nuclei and cytoplasm of 38 FFPE specimens were assessed by immunohistochemistry; HPV genotype was detected by qPCR assay; EGFR mutation was assessed by DNA sequencing analysis; and EGFR mRNA expression was measured using relative qPCR. Statistical analyses included two-sided Fisher exact test or chi-square test, Spearman correlation coefficient and ANOVA. HPV 18 was found in 61% of samples, with HPV 16 double-genotype in 6 patients (16%). Immunohistochemistry and qPCR data suggest that activation and expression of the EGFR signaling pathway is related to disease progression of conjunctival cancer. The associations between cytoplasmic p-MAPK, cytoplasmic p-Akt and tumor invasiveness were significant (p = 0.05 or 0.028). Nuclear p-EGFR appeared only in invasive tumors. A significant positive association between EGFR expression and disease invasiveness was observed (p = 0.01). A SNP in 10 patients and one missense mutation were found within EGFR tyrosine kinase domain. Statistical analysis indicates that patients with measurable EGFR expression more likely harbor EGFR mutations, compared to those with negative EGFR expression (35.3% vs. 0%). Conclusions/Significance We conclude that HPV types 16/18 infection is frequent in East African patients with AIDS-associated squamous cell carcinoma of the conjunctiva. EGFR activation/alteration may contribute to and sustain the high prevalence of this cancer. Our findings hint that adoption of HPV vaccination strategies may impact the incidence of conjunctival carcinoma. Agents that target the EGFR pathway may have potential therapeutic benefit

HPV Infection and EGFR Activation/Alteration in HIV-Infected East African Patients with Conjunctival Carcinoma

Background There has been substantial growth in the numbers of patients with conjunctival squamous cell carcinoma infected with HIV in East Africa. The natural history of the conjunctival squamous cell carcinoma appears to be unique in this region of the world, but the etiologic mechanism unclear and therapeutic options limited. This research was carried out to determine if conjunctival squamous cell carcinoma harbors human papillomavirus DNA and is associated with activation of the EGFR signaling pathway. Positive findings would identify etiologic causes and provide clinical guidance to improve treatment. Methods/Findings Expression of p-MAPK/MAPK, p-Akt/Akt and p-EGFR/EGFR in cell nuclei and cytoplasm of 38 FFPE specimens were assessed by immunohistochemistry; HPV genotype was detected by qPCR assay; EGFR mutation was assessed by DNA sequencing analysis; and EGFR mRNA expression was measured using relative qPCR. Statistical analyses included two-sided Fisher exact test or chi-square test, Spearman correlation coefficient and ANOVA. HPV 18 was found in 61% of samples, with HPV 16 double-genotype in 6 patients (16%). Immunohistochemistry and qPCR data suggest that activation and expression of the EGFR signaling pathway is related to disease progression of conjunctival cancer. The associations between cytoplasmic p-MAPK, cytoplasmic p-Akt and tumor invasiveness were significant (p = 0.05 or 0.028). Nuclear p-EGFR appeared only in invasive tumors. A significant positive association between EGFR expression and disease invasiveness was observed (p = 0.01). A SNP in 10 patients and one missense mutation were found within EGFR tyrosine kinase domain. Statistical analysis indicates that patients with measurable EGFR expression more likely harbor EGFR mutations, compared to those with negative EGFR expression (35.3% vs. 0%). Conclusions/Significance We conclude that HPV types 16/18 infection is frequent in East African patients with AIDS-associated squamous cell carcinoma of the conjunctiva. EGFR activation/alteration may contribute to and sustain the high prevalence of this cancer. Our findings hint that adoption of HPV vaccination strategies may impact the incidence of conjunctival carcinoma. Agents that target the EGFR pathway may have potential therapeutic benefit

Effect of preoperative intravenous oxycodone administration on sufentanil consumption after retroperitoneal laparoscopic nephrectomy

  BACKGROUND: The aim of this study was to evaluate the efficacy of preoperative intravenous oxycodone administration on postoperative sufentanil consumption in patients undergoing retroperitoneal laparoscopic nephrectomy. METHODS: Fifty patients scheduled for retroperitoneal laparoscopic nephrectomy were enrolled and randomly assigned to two groups — patients in Group O (n = 25) received intravenously 0.1 mg kg-1 oxycodone; while the patients in Group C (n = 25) received 0.1 mL kg-1 normal saline for 2 min, 10 min before the operation. All of the participants received intravenous sufentanil patient-controlled analgesia (PCA) after extubation, using a PCA device. The sufentanil consumption, rescue analgesia, Ramsay sedation scale (RSS) and visual analogue scale (VAS) scores at rest and during cough, the overall satisfaction and undesired events were all assessed. RESULTS: Cumulative sufentanil consumption delivered by PCA was significantly lower in Group O at all time points. VAS scores at rest and during coughing at 1, 2, 4, 8 and 12 hours after extubation of the patient were significantly lower in Group O than in Group C. There were no significant differences between the two groups according to the number of patients administered tramadol, RSS and the incidence of side effects. The degree of patients’ satisfaction was higher in Group O. CONCLUSION: Preoperative intravenous oxycodone can reduce postoperative cumulative sufentanil consumption and postoperative pain intensity without an increase in side effects.  BACKGROUND: The aim of this study was to evaluate the efficacy of preoperative intravenous oxycodone administration on postoperative sufentanil consumption in patients undergoing retroperitoneal laparoscopic nephrectomy. METHODS: Fifty patients scheduled for retroperitoneal laparoscopic nephrectomy were enrolled and randomly assigned to two groups — patients in Group O (n = 25) received intravenously 0.1 mg kg-1 oxycodone; while the patients in Group C (n = 25) received 0.1 mL kg-1 normal saline for 2 min, 10 min before the operation. All of the participants received intravenous sufentanil patient-controlled analgesia (PCA) after extubation, using a PCA device. The sufentanil consumption, rescue analgesia, Ramsay sedation scale (RSS) and visual analogue scale (VAS) scores at rest and during cough, the overall satisfaction and undesired events were all assessed. RESULTS: Cumulative sufentanil consumption delivered by PCA was significantly lower in Group O at all time points. VAS scores at rest and during coughing at 1, 2, 4, 8 and 12 hours after extubation of the patient were significantly lower in Group O than in Group C. There were no significant differences between the two groups according to the number of patients administered tramadol, RSS and the incidence of side effects. The degree of patients’ satisfaction was higher in Group O. CONCLUSION: Preoperative intravenous oxycodone can reduce postoperative cumulative sufentanil consumption and postoperative pain intensity without an increase in side effects