Thermal Stability of (Bio)Carbonates: A Potential Signature for Detecting Life on Mars?

The environmental conditions that prevail on the surface of Mars (i.e., high levels of radiation and oxidants) are not favorable for the long-term preservation of organic compounds on which all strategies for finding life on Mars have been based to date. Since life commonly produces minerals that are considered more resilient, the search for biominerals could constitute a promising alternative approach. Carbonates are major biominerals on Earth, and although they have not been detected in large amounts at the martian surface, recent observations show that they could constitute a significant part of the inorganic component in the martian soil. Previous studies have shown that calcite and aragonite produced by eukaryotes thermally decompose at temperatures 15°C lower than those of their abiotic counterparts. By using carbonate concretions formed by microorganisms, we find that natural and experimental carbonates produced by prokaryotes decompose at 28°C below their abiotic counterparts. The study of this sample set serves as a proof of concept for the differential thermal analysis approach to distinguish abiotic from bio-related carbonates. This difference in carbonate decomposition temperature can be used as a first physical evidence of life on Mars to be searched by in situ space exploration missions with the resolution and the technical constraints of the available onboard instruments.

Clinical characteristics and outcomes after extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest patients with an initial asystole rhythm

AIM

This study aimed to describe the characteristics of cases of out-of-hospital cardiac arrest (OHCA) with an initial asystole rhythm in which extracorporeal cardiopulmonary resuscitation (ECPR) was introduced and discuss the clinical indications for ECPR in such patients.

METHODS

This was a secondary analysis of the SAVE-J II study, a retrospective, multicentre, registry study involving 36 participating institutions in Japan. Patients with an initial asystole rhythm were selected. Favourable neurological outcomes (cerebral performance categories 1-2) constituted the primary outcome.

RESULTS

In total, 202 patients met the inclusion criteria, with favourable neurological outcomes at hospital discharge in 12 patients (5.9%). Causes of cardiac arrest with favourable neurological outcomes were hypothermia (7 cases), acute coronary syndrome (2 cases), arrhythmia (2 cases), and pulmonary embolism (1 case). Among patients with non-hypothermia (temperature ≥32 °C) on hospital arrival with the cardiac rhythm of asystole or pulseless electrical activity (PEA) on arrival, all 107 patients (66 asystole, 41 PEA) who lacked one or more of the requirements (witness; bystander CPR; signs of life or pupil < 5 mm) had unfavourable neurological outcomes. All 5 cases with favourable neurological outcomes, except for 1 case with a short duration of no-flow time that was highly suspected based on the patient's history, met all the requirements on hospital arrival.

CONCLUSIONS

A total of 202 ECPR cases with an initial asystole rhythm, including 12 patients with favourable neurological outcomes, were described. Even if the initial cardiac rhythm is asystole, ECPR could be considered if certain conditions are met.

Impact of trauma level designation on survival of patients arriving with no signs of life to US trauma centers

BACKGROUND

Trauma level designation and verification are examples of healthcare regionalization aiming at improving patient outcomes. This study examines impact of Trauma Levels on survival of patients arriving with "no signs of life" to US trauma centers.

METHODS

This retrospective study used the US National Trauma Data Bank (NTDB) 2015 dataset. A descriptive followed by a bivariate analysis was done comparing variables by the trauma designation levels. A multivariate analysis assessed the effect of the trauma designation on survival to hospital discharge after controlling for potential confounding factors.

RESULTS

6160 patients without signs of life were included. The average age was 40.66 years (±19.96) with male predominance (77.3%). Most patients were transported using ground ambulance (83.5%) and were taken to Level I (57%) and Level II (32.4%) centers. Blunt injuries were the most common (56.9%). Motor Vehicle Collision (MVC) (38.5%) and firearm (33.8%) were the most common mechanisms of injury. Survival to hospital discharge among patients with no signs of life ranged from 13.7% at Level I to 27.9% at Level III. After adjusting for confounders, including Injury Severity Score (ISS), higher survival was noted at Level II trauma centers compared to Level I.

CONCLUSIONS

Patients presenting without signs of life to Level II trauma centers had higher survival to hospital discharge compared to Level I and Level III centers. These findings can guide future prehospital triage criteria of trauma patients in organized Emergency Medical Services (EMS) systems and highlight the need for more outcome research on trauma systems.

Influence of psychological nursing intervention on signs of life and anxiety in patients with esophageal cancer

AIM: To explore the influence of psychological nursing intervention on signs of life and anxiety in patients with esophageal cancer.

METHODS: Eighty-four patients with esophageal cancer were randomly divided into either a control group or an experiment group. The control group received routine nursing, and the experiment group was additionally given psychological nursing intervention on the basis of routine nursing. The score of self-rating anxiety scale (SAS), heart rate, blood pressure, diastolic blood pressure, breathing rate, and pulse rate were compared for the two groups.

RESULTS: The score of SAS was significantly lower after intervention than before intervention for the two groups (35.67 ± 5.72 vs 45.33 ± 6.34, 40.51 ± 5.91 vs 46.82 ± 6.77, P < 0.05), and in the experiment group than in the control group after intervention (35.67 ± 5.72 vs 40.51 ± 5.91, P < 0.05). The levels of heart rate, blood pressure, diastolic blood pressure, breathing rate and pulse rate were significantly higher after intervention than before intervention in the control group (85.73/min ± 6.89/min vs 76.78/min ± 5.73/min, 133.78 mmHg ± 9.94 mmHg vs 107.55 mmHg ± 8.95 mmHg, 75.47 mmHg ± 6.77 mmHg vs 68.27 mmHg ± 4.44 mmHg, 28.45/min ± 0.66/min vs 24.67/min ± 1.45/min, 126.47 mmHg ± 6.77 mmHg vs 118.27 mmHg ± 4.44 mmHg, P < 0.05), but showed no significant difference for the experiment group (78.03/min ± 4.26/min vs 77.33/min ± 5.78/min, 112.45 mmHg ± 5.79 mmHg vs 106.46 mmHg ± 8.58 mmHg, 68.05 mmHg ± 3.68 mmHgvs 68.84 mmHg ± 5.78 mmHg, 23.78/min ± 0.44/min vs 25.54/min ± 1.67/min, 115.05 mmHg ± 6.68 mmHg vs 119.84 mmHg ± 6.78 mmHg, P > 0.05). The levels of heart rate, blood pressure, diastolic blood pressure, breathing rate, and pulse rate after intervention were significantly lower in the experiment group than in the control group (P < 0.05).

CONCLUSION: Psychological nursing intervention can relieve anxiety, keep the heart rate, blood pressure, breathing, and pulse stable, and promote recovery in patients with esophageal cancer.