A biomarker panel of C-reactive protein, procalcitonin and serum amyloid A is a predictor of sepsis in severe trauma patients.

Severe trauma could induce sepsis due to the loss of control of the infection, which may eventually lead to death. Accurate and timely diagnosis of sepsis with severe trauma remains challenging both for clinician and laboratory. Combinations of markers, as opposed to single ones, may improve diagnosis. We compared the diagnostic characteristics of routinely used biomarkers of sepsis alone and in combination, trying to define a biomarker panel to predict sepsis in severe patients. This prospective observational study included patients with severe trauma (Injury severity score, ISS = 16 or more) in the emergency intensive care unit (EICU) at a university hospital. Blood samples were collected and plasma levels of procalcitonin (PCT), C-reactive protein (CRP), interleukin-6 (IL-6) and serum amyloid A (SAA) were measured using commercial enzyme linked immunosorbent assay (ELISA) kits. A total of 100 patients were eligible for analysis. Of these, 52 were diagnosed with sepsis. CRP yielded the highest discriminative value followed by PCT. In multiple logistic regression, SAA, CRP, and PCT were found to be independent predictors of sepsis. Bioscore which was composed of SAA, CRP, and PCT was shown to be far superior to that of each individual biomarker taken individually. Therefore, compared with single markers, the biomarker panel of PCT, CRP, and SAA was more predictive of sepsis in severe polytrauma patients.

[Spatial and Temporal Variation of Phytoplankton Community Structure and Its Influencing Factors in Shanghai River Channels].

In order to explore the spatial and temporal characteristics of the phytoplankton community structure and its influencing factors in Shanghai rivers, the water quality and phytoplankton community structure at 44 river channel sites in a central urban area, new town area, and rural area in Shanghai were investigated from September to October 2018 (autumn) and July to August 2019 (summer). The results showed that:① Chlorophyta was the dominant phyla during the autumn and summer, and was followed by Cyanobacteria and Bacillariophyta. Cyanobacteria dominated the phytoplankton community in terms of density. The number of species and density of phytoplankton were 24% and 2.77 times higher, respectively, than those during the summer and autumn. The dominance of Microcystis sp. was obvious during the autumn (Y=0.16), but there was no absolute dominant species during the summer. ② The difference in the number of phytoplankton species among the three regions was not significant, and the density of the total phytoplankton and cyanobacteria species showed a similar spatial pattern:rural area > new town area > central urban area. Additionally, no significant difference was observed in the total phytoplankton and Cyanobacteria density among the three regions during the autumn (P>0.05), whereas it was 1.82 and 1.93 times higher, respectively, in the rural area in comparison to the central urban area during the summer (P<0.05). Montecarlo test results revealed that the main factors affecting the phytoplankton community structure during the autumn were secchi disk transparency (SD), total phosphorus (TP), total nitrogen (TN), and turbidimetry (Turb), whereas these were TN, Turb, SD, and pH during the summer. ③ The results of a redundancy analysis (RDA) indicated that during the autumn, the phytoplankton in the rivers of the new town area were mainly affected by Turb, TN, and TP, while the rural rivers were mainly affected by SD. During the summer, the phytoplankton in the rivers of the new town and rural areas were mainly affected by TN and Turb. The influencing factors in the central urban area were complex.

The Healing Rate of Type II Odontoid Fractures Treated With Posterior Atlantoaxial Screw-rod Fixation: A Retrospective Review of 77 Patients.

BACKGROUND: In theory, temporary posterior atlantoaxial screw-rod fixation for type II odontoid fractures is a way to preserve rotatory motion. However, the healing rate of type II odontoid fractures treated in this way is unknown; that is, the risk associated with conducting a temporary screw-rod fixation for type II odontoid fractures is unknown. This study investigates the healing rate of type II odontoid fractures treated with posterior atlantoaxial screw-rod fixation by CT imaging and evaluates the feasibility of conducting a temporary screw-rod fixation for type II odontoid fractures. METHODS: Patients with type II odontoid fracture who underwent posterior atlantoaxial screw-rod fixation in our spine center from January 2011 to December 2014 were identified. Patients older than 65 years or younger than 18 years were excluded. Those who were confirmed to have healing odontoid fractures on CT imaging were included. Those in whom fracture healing was not confirmed were asked to undergo a CT examination. Fracture healing was confirmed on the basis of the presence of bridging bone across the odontoid fracture site on CT imaging. RESULTS: Seventy-seven patients (56 men and 21 women) were included in the study. The average age of the patients was 40.7 ± 11.6 years (range, 18 to 64 years). The mean duration of follow-up was 26.4 ± 4.6 months (range, 24 to 40 months). Fracture healing was observed in 73 patients (94.8%). DISCUSSION: The healing rate of type II odontoid fractures (with an age range of 18 to 64 years) treated with modern posterior atlantoaxial fixation is relatively high. For patients at that age range, posterior atlantoaxial temporary screw-rod fixation for type II odontoid fractures can be conducted with a low risk of nonunion. LEVEL OF EVIDENCE: Level IV, therapeutic.

Posterior atlantoaxial fusion with a screw-rod system: Allograft versus iliac crest autograft.

OBJECTIVE: To compare the effectiveness of allograft and iliac crest autograft in atlantoaxial fusion. PATIENTS AND METHODS: Between January 2012 and December 2012, 41 consecutive patients underwent posterior atlantoaxial fusion with a screw-rod fixation system in our spine center. The choice to use allograft or iliac crest autograft was made by the patient himself or herself after being informed about the advantages and disadvantages of both methods. In the allograft group, we used mixed material of morcellized demineralized freeze-dried bone allograft and local autograft for posterior atlantoaxial fusion. In the autograft group, we used the morcellized iliac crest autograft for fusion. Patients underwent regular follow up including CT scans and dynamic radiographs 6 months postoperatively and every 6 months thereafter until study completion or confirmation of fusion. RESULTS: Twenty-four patients underwent posterior atlantoaxial fusion with allograft, and 17 underwent fusion with autograft. All patients were followed up for at least 24 months. At the final follow-up visit, only two (8.3%) patients in the allograft group had confirmed posterior bony fusion on CT imaging while 15 (88.2%) patients in the autograft group had confirmed posterior bony fusion. None of the 41 patients had movement on the dynamic radiographs. CONCLUSIONS: Allograft is not reliable for posterior atlantoaxial fusion even with the rigid internal fixation of modern constructs. Autograft remains the first choice for atlantoaxial fusion despite the donor-site morbidity. The assessment of fusion based on a lack of movement on dynamic radiographs is not reliable. The confirmation of fusion should be based on the presence of bridging bone on CT imaging.

Orbital angular momentum complex spectrum analyzer for vortex light based on the rotational Doppler effect.

The ability to measure the orbital angular momentum (OAM) distribution of vortex light is essential for OAM applications. Although there have been many studies on the measurement of OAM modes, it is difficult to quantitatively and instantaneously measure the power distribution among different OAM modes, let alone measure the phase distribution among them. In this work, we propose an OAM complex spectrum analyzer that enables simultaneous measurements of the power and phase distributions of OAM modes by employing the rotational Doppler effect. The original OAM mode distribution is mapped to an electrical spectrum of beat signals using a photodetector. The power and phase distributions of superimposed OAM beams are successfully retrieved by analyzing the electrical spectrum. We also extend the measurement technique to other spatial modes, such as linear polarization modes. These results represent a new landmark in spatial mode analysis and show great potential for applications in OAM-based systems and optical communication systems with mode-division multiplexing.

The feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus: a retrospective analysis of eleven patients.

BACKGROUND: Ponticulus posticus is a common anatomic variation that can be mistaken for a broad posterior arch during C1 pedicle screw placement. When the atlas lateral mass screws are placed via the posterior arch, injury to the vertebral artery may result. To our knowledge, there are few clinical studies that have analyzed the feasibility of C1 pedicle screw fixation in patients with ponticulus posticus, in clinical practice. PURPOSE: To evaluate the feasibility of inserting a C1 pedicle screw in patients with ponticulus posticus. METHODS: Between January 2008 and January 2012, 11 consecutive patients with atlantoaxial instability, and with a ponticulus posticus at C1, underwent posterior fusion surgery in our institution. According to preoperative computed tomography (CT) reconstruction, a complete ponticulus posticus was found unilaterally in nine patients and bilaterally in two. Postoperative CT reconstructive imaging was performed to assess whether C1 pedicle screw placement was successful. Patients were followed up at regular intervals and evaluated for symptoms of ponticulus posticus syndrome. RESULTS: Thirteen C1 pedicles (atlas vertebral artery groove), each with a complete ponticulus posticus, were successfully inserted with thirteen 3.5- or 4.0-mm diameter pedicle screws, without resection of the bony anomaly. No intraoperative complications (venous plexus, vertebral artery, or spinal cord injury) occurred. The mean follow-up period was 21 (range 14-30) months. Postoperative CT reconstructive images showed that all 13 pedicle screws were inserted in the C1 pedicles without destruction of the atlas pedicle cortical bone. In the follow-up period, none of the patients demonstrated clinical symptoms of ponticulus posticus syndrome or developed bone fusion. CONCLUSION: Three-dimensional CT imaging should be considered prior to C1 pedicle screw fixation in patients with ponticulus posticus, to avoid mistaking the ponticulus posticus for a widened dorsal arch of the atlas. If there is no ponticulus posticus syndrome preoperatively, C1 pedicle screw fixation can be successfully performed without removing the bony anomaly.

Terahertz-bandwidth photonic temporal differentiator based on a silicon-on-isolator directional coupler.

We experimentally demonstrate a terahertz-bandwidth photonic differentiator employing a silicon-on-insulator directional coupler. The integrated waveguide coupler with two identical paralleled strip waveguides achieves a first-order differentiator when full energy coupling is met from one waveguide to another. The integrated waveguide coupler can offer different operation bandwidths by changing the length and gap of the strip waveguides. Due to the large 3 dB bandwidth of the directional coupler, we implement the first differentiator with an operation bandwidth of 1.25 THz. The performance of this photonic differentiator is tested using Gaussian-like pulses with a pulsewidth of 2.8 ps, 4 ps, 6 ps, 8 ps, and 10 ps, respectively. The differentiation processing errors and relative energy efficiency are also discussed. This silicon chip may have potential applications in integrated photonic computing circuits with sub-picosecond pulses.

Cardioprotective effect of erythropoietin on sepsis-induced myocardial injury in rats.

BACKGROUND: Sepsis-induced myocardial injury is one of the major predictors of morbidity and mortality of sepsis. The cytoprotective function of erythropoietin (EPO) has been discovered and extensively studied. However, the cardioprotective effects of EPO on sepsis-induced myocardial injury in the rat sepsis model has not been reported. METHODS: The rat models of sepsis were produced by cecal ligation and perforation (CLP) surgery. Rats were randomly (random number) assigned to one of three groups (n=8 for each group): sham group, CLP group and EPO group (1000 IU/kg erythropoietin). Arterial blood was withdrawn at 3, 6, 12, and 24 hours after CLP. cTnI, BNP, CK-MB, LDH, AST, TNF-α, IL-6, IL-10, and CRP were tested by the ELISA assay. Changes of hemodynamic parameters were recorded at 3, 6, 12, 24 hours after the surgery. Histological diagnosis was made by hematoxylin and eosin. Flow cytometry was performed to examine cell apoptosis, myocardium mitochondrial inner membrane potential, and NF-κB (p65). Survival rate at 7 days after CLP was recorded. RESULTS: In the CLP group, myocardial enzyme index and inflammatory index increased at 3, 6, 12 and 24 hours after CLP compared with the sham group, and EPO significantly blocked the increase. Compared with the CLP group, EPO significantly improved LVSP, LV +dp/dt max, LV -dp/dt min, and decreased LVEDP at different time. EPO blocked the reduction of mitochondrial transmembrane potential, suppressed the cardiomyocyte apoptosis, inhibited the activation of NF-κB, and reduced the production of proinflmmatory cytokines. No difference in the survival rate at 7 days was observed between the CLP group and the EPO group. CONCLUSION: Exogenous EPO has cardioprotective effects on sepsis-induced myocardial injury.

[Effects of fluid resuscitation on myocardial injury in patients with severe sepsis and septic shock].

OBJECTIVE: To observe the influence of fluid resuscitation on patients suffered from myocardial injury with severe sepsis and septic shock, and to evaluate the markers of myocardial injury during fluid resuscitation. METHODS: Acute physiology and chronic health evaluation II (APACHE II) score of 78 patients with severe sepsis and septic shock induced by combined injuries was 18-35. Serum cardiac troponin I (cTnI), N-terminal-ventricular natriuretic peptide precursor (NT-proBNP) and the hemodynamic parameters were recorded before, 3 days, and 5 days after treatment, and correlative analysis was conducted. RESULTS: Serum cTnI was increased in 62.8% (49/78) patients with severe sepsis and septic shock, and in 73.5% of patients (36/49) the increase was greater than 2-fold of the borderline value, and in 30.6% of patients (15/49) was greater than 4-fold of the borderline value. The patients with elevated serum NT-proBNP at admission accounted for 46.2% (36/78), and after fluid resuscitation treatment, patients with continuously rising value accounted for 74.4% (58/78). The serum cTnI, NT-proBNP, pulmonary arterial wedge pressure (PAWP) and cardiac index (CI) after treatment in survival group (55 cases) were obviously improved, and changes in them in non-survival group (23 cases) was not obvious. The serum cTnI (µg/L) and NT-proBNP (ng/L) levels in the non-survival group were distinctly higher than those of the survival group (cTnI 3 days: 2.09 ± 1.00 vs. 1.57 ± 0.93, 5 days: 1.78 ± 0.67 vs. 0.72 ± 0.51; NT-proBNP 3 days: 3.52 ± 0.73 vs. 3.16 ± 0.65, 5 days: 3.21 ± 0.66 vs. 2.66 ± 0.58), and CI [ml·s(-1)·m(-2)] was obviously lower than that of the survival group (3 days: 57.6 ± 6.2 vs. 68.3 ± 5.6, 5 days: 40.5 ± 4.7 vs. 80.7 ± 6.8, all P < 0.05). The cTnI level (µg/L) of 46 patients whose fluid resuscitation achieved the target was lower than that of the 32 cases without achieving the target (1.16 ± 0.62 vs. 1.97 ± 0.76, P < 0.05), and the CI [ml·s(-1)·m(-2)] was obviously increased (61.2 ± 6.4 vs. 49.3 ± 6.1, P < 0.05). The results suggested that whether the fluid resuscitation achieved the target or not was not related to changes in serum NT-proBNP and PAWP. A positive correlation was found between serum cTnI and NT-proBNP (r = 0.865, Y = 2.069 + 0.695X, P < 0.01), also between NT-proBNP and PAWP (r = 0.762, Y = 1.125 + 4.929X, P < 0.01), and a negative correlation was found between cTnI and CI (r = -0.891, Y = 50.623 - 6.114X, P < 0.01). CONCLUSIONS: There is an obvious myocardial injury in the patient with severe sepsis and septic shock, and fluid resuscitation can improve the myocardial injury; the serum levels of cTnI and NT-proBNP are related to the prognosis of patients, but the significance of NT-proBNP guiding the fluid resuscitation can not be ascertained.

[Relationship between hepatitis B virus DNA and hepatitis B virus large envelope protein].

OBJECTIVE: To investigate the relationship between HBV DNA and hepatitis B virus large envelope protein (HBV-LP) in patients with chronic hepatitis B. METHODS: Serum HBV DNA was detected by RT-PCR and the HBV-LP was detected by enzyme linked immunosorbent assay in 320 serum samples collected from patients with chronic hepatitis B. RESULTS: There were no significant difference between positive rate of HBV-LP and that of HBV DNA in different HBeAg patterns (P>0.05). Serum HBV-LP levels were closely correlated with HBV DNA copies (r=0.949). CONCLUSION: Serum HBV-LP is a reliable serological marker that can reflect the replication of HBV.

Ultrahigh-speed all-optical half adder based on four-wave mixing in semiconductor optical amplifier.

A novel scheme for an ultrahigh-speed all-optical half adder based on four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is proposed. This scheme is free of pattern effect, due to using the polarization-shift-keying (PolSK) modulation format. By numerical simulation, the output power level of logic "1" dependence on the operating conditions, such as two input signal powers, injection current, and input signal wavelength, are investigated in detail using the broad-band model of this all-optical half adder.