Outcomes of Patients Undergoing Elective Cancer Surgery After SARS-CoV-2 Infection: An Observational Cohort Study.

BACKGROUND: We evaluated the impact of preoperative SARS-CoV-2 infections on postoperative outcomes among patients undergoing elective cancer surgery. METHODS: This ambidirectional (retrospective and prospective) study was conducted among patients undergoing elective cancer surgery between December 2022 and March 2023. Patients with different time intervals between SARS-CoV-2 infection and surgery (0-6 weeks and ≥7 weeks) were compared with those without SARS-CoV-2 infection. The primary outcome was 30-day postoperative pulmonary complications (PPCs). Secondary outcomes included 30-day postoperative mortality, major adverse cardiovascular events (MACE), and other postoperative adverse outcomes. RESULTS: Of the 830 patients analyzed, 239 (28.8%) had SARS-CoV-2 infection 0-6 weeks before cancer surgery, and they had a higher incidence of PPCs (4.6% in no SARS-CoV-2 infection, 12.1% in 0-6 weeks, and 5.1% in ≥7 weeks, p = 0.001). The logistic regression model revealed that, compared with patients without SARS-CoV-2 infection, surgery performed 0-6 weeks after SARSCoV-2 infection was associated with a higher risk of PPCs (adjusted odds ratio [aOR] 2.83; 95% confidence interval [CI] 1.34-5.98), and surgery performed ≥7 weeks after SARSCoV-2 infection was associated with a similar risk of PPCs (aOR 1.19; 95% CI 0.54-2.64). However, preoperative SARS-CoV-2 infection was not associated with a risk of 30-day postoperative mortality, MACE, or other adverse postoperative outcomes. CONCLUSIONS: In patients with preoperative Omicron variant infection, nonemergency cancer surgery can be scheduled ≥7 weeks after the infection to decrease the risk of PPCs, but it can be advanced if the risk of delay exceeds the risk of proceeding with the surgery.

1.8 W, high efficiency, pump-enhanced, narrow linewidth optical parametric oscillator at 3.8 µm.

A high efficiency, continuous-wave, narrow linewidth, pump-enhanced optical parametric oscillator (OPO) at 3.8 µm was demonstrated, which was pumped by a 1064 nm fiber laser with a linewidth of 18 kHz. The low frequency modulation locking technique was employed to stabilize the output power. The wavelengths of signal and idler were 1475.5 nm and 3819.9 nm at 25 °C, respectively. The pump-enhanced structure was applied, leading to a maximum quantum efficiency of over 60% with pump power of 3 W. The maximum output power of idler light is 1.8 W with a linewidth of 363 kHz. The excellent tuning performance of the OPO was also demonstrated. In order to avoid mode-splitting and decrease of pump enhancing factor due to feedback light in the cavity, the crystal was placed obliquely to the pump beam and the maximum output power was increased by 19%. At the maximum output power of idler light, the M2 factors in the x and y directions were 1.30 and 1.33, respectively.

Multi-pulse dynamic patterns in a mode-locked erbium-doped fiber laser based on an Sb2S3-PVA saturable absorber.

Multi-pulse dynamic patterns have been experimentally documented in a passively mode-locked (PML) erbium-doped fiber (EDF) laser using an Sb2S3-PVA saturable absorber (SA). The fundamental mode-locking operation, with a repetition rate of ∼3.22 MHz, a pulse width of ∼2.5 ps, a signal-to-noise ratio (SNR) of ∼50 dB and a peak power over 200 W, was achieved under a pump power from 280 to 360 mW with appropriate polarization states introduced by the polarization controllers (PCs). By rotating the orientation of the intra-cavity PCs carefully and slowly at a pump power of 350 mW, it was found that a multi-pulse bunch was transformed gradually from a single-pulse to a twelve-pulse bunch, with several intermediate transition states of multi-pulse bunches being observed. In addition, other characteristic modes including disordered multi-pulses and soliton rains have been experimentally observed by meticulously adjusting the polarization states of PCs at a pump power of 350 mW. Our systematic study clearly demonstrates that Sb2S3has potential as an effective SA for generating different operation states of multi-pulses in PML anomalous-dispersion EDF lasers.

Noise-like pulse generation in an Nd-doped single-mode all-fiber mode-locked Raman laser operating at 0.93 µm.

Based on the Nd-doped single-mode fiber (SMF) as the gain medium and SMF as the Raman medium, an all-fiber mode-locked Raman laser operating at 0.93 µm waveband was demonstrated for the first time. A mandrel with a diameter of 10 mm was employed to introduce bending losses to suppress the dominant emission of Nd-doped fiber at 1.06 µm. A noise-like pulse with a pulse width of 194.70 fs, a repetition rate of 1.73 MHz and a single pulse energy of 2.03 nJ was obtained in the mode-locked Raman laser with a Stokes wavelength of 932.59 nm. Such an ultrafast all-fiber Raman laser operating at 0.93 µm has the advantages of low cost, simple structure and compactness, and can be used as an ideal light source for the two-photon microscopy.

Passively Mode-Locked Er-Doped Fiber Laser Based on Sb2S3-PVA Saturable Absorber.

In this paper, antimony trisulfide (Sb2S3) was successfully prepared with the liquid phase exfoliation method and embedded into polyvinyl alcohol (PVA) as a saturable absorber (SA) in a passively mode-locked Er-doped fiber laser for the first time. Based on Sb2S3-PVA SA with a modulation depth of 4.0% and a saturable intensity of 1.545 GW/cm2, a maximum average output power of 3.04 mW and maximum peak power of 325.6 W for the stable mode-locked pulses was achieved with slope a efficiency of 0.87% and maximum single pulse energy of 0.81 nJ at a repetition rate of 3.47 MHz under a pump power of 369 mW. A minimum pulse width value of 2.4 ps with a variation range less than 0.1 ps, and a maximum signal to noise ratio (SNR) of 54.3 dB indicated reliable stability of mode-locking, revealing promising potentials of Sb2S3 as a saturable absorber in ultrafast all-fiber lasers.

Passively Q-switched Yb-doped dual-wavelength fiber laser based on a gold-nanocage saturable absorber.

In this paper, we demonstrate a passively Q-switched Yb-doped dual-wavelength fiber laser using gold nanocages (GNCs) as a saturable absorber. The GNCs are prepared by the seed-mediated method with modulation depth of 5.3% and saturable intensity of 0.16 MW/cm2. A simultaneous dual-wavelength operation is achieved at 1059.9 and 1060.5 nm with 3 dB bandwidths of 0.05 and 0.04 nm, respectively. A maximum average output power of 6.03 mW with minimum pulse width of 2.06 µs and maximum repetition rate of 134.9 kHz is obtained at a pump power of 385 mW, corresponding to optical-to-optical conversion efficiency of 1.57% and slope efficiency of 2.75%.

Impact of preoperative inflammatory and nutritional markers on the prognosis of patients with peritoneal metastasis of colorectal cancer.

BACKGROUND: Identifying patients with peritoneal metastasis (PMs) of colorectal cancer (CRC) who will benefit from cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is crucial before surgery. Inflammatory and nutritional indicators play essential roles in cancer development and metastasis. AIM: To investigate the association of preoperative inflammatory and nutritional markers with prognosis in patients with CRC-PM. METHODS: We included 133 patients diagnosed with CRC-PM between July 2012 and July 2018. Patients' demographics, overall survival (OS), and preoperative inflammatory and nutritional markers were evaluated. The Kaplan-Meier method and log-rank test were used to estimate differences. RESULTS: Of the 133 patients, 94 (70.6%) had normal hemoglobin (Hb) and 54 (40.6%) had a high neutrophil-to-lymphocyte ratio (NLR). The median OS (mOS) was significantly lower for patients with high NLR (7.9 months) than for those with low NLR (25.4 months; P = 0.002). Similarly, patients with normal Hb had a longer mOS (18.5 months) than those with low Hb (6.3 months; P < 0.001). Multivariate analysis identified age, carbohydrate antigen 199 levels, NLR, Hb, and peritoneal cancer index as independent predictors of OS. Based on these findings, a nomogram was constructed, which demonstrated a good capacity for prediction, with a C-index of 0.715 (95% confidence interval: 0.684-0.740). Furthermore, the 1- and 2-year survival calibration plots showed good agreement between predicted and actual OS rates. The areas under the curve for the 1- and 2-year survival predictions of the nomogram were 0.6238 and 0.6234, respectively. CONCLUSION: High NLR and low Hb were identified as independent predictive risk factors for poor prognosis in patients with CRC-PM. The established nomogram demonstrated high accuracy in predicting OS for patients with CRC-PM, indicating its potential as a valuable prognostic tool for this patient population.

Reliability of pressure cuff induced transient limb ischemia in conscious rabbits.

BACKGROUND: The protective effects of transient limb ischemia (TLI) induced by several cycles of intermittent pressure cuff inflation and deflation for a period have been widely investigated, however the reliability of this protocol has not been clearly verified. Our study aimed to investigate the reliability of pressure cuff induced TLI in conscious rabbits. METHODS: Eight New Zealand rabbits were subjected to TLI without anesthesia. TLI consisted of 3 cycles of ischemia and reperfusion induced by inflating the cuff placed on the left lower limb to 200 mmHg for 5 minutes followed by deflating the cuff for 5 minutes. Skin color, pulse oxygen saturation (SpO2), pulse rate (PR), plethysmogram waveform (Pleth), and ultrasound detection of the blood flow in the extremity distal to the ischemic segment were observed to confirm ischemia and reperfusion during TLI. The frequency of severe limb movement during TLI was also recorded to assess the amenability of this protocol in conscious rabbits. RESULTS: The skin color of the extremity distal to the ischemic segment changed from bright red to dark purple after inflating the cuff to 200 mmHg, and returned to normal after cuff deflation. Pleth, PR and SpO2 disappeared during ischemia and restored during reperfusion in the monitor. Blood flow of the left posterior tibial artery was completely blocked by a pressure of 200 mmHg during ischemia, and recovered immediately after cuff deflation. The frequency of severe limb movement in supine position was higher than that in prone position (P < 0.05), but there was no severe limb movement that could result in disturbance to ischemia when the rabbits were placed in prone position. CONCLUSION: Pressure cuff inflating to 200 mmHg for 5 minutes and deflating for 5 minutes is a reliable regimen to induce TLI in conscious rabbits.