FLOWERS IN THE SICKROOM

Carbon dioxide output in laparoscopic cholecystectomy

To the Editor:— InThe Journal, Nov. 30, 1935, Drs. L. J. Robinson and Sydney Selesnick presented an interesting and valuable discussion of the treatment of acute alcoholism with 10 per cent carbon dioxide and 90 per cent oxygen. They did not undertake to decide whether oxygen is really needed along with carbon dioxide, or whether carbon dioxide alone, which is far less expensive, would not be entirely adequate. What I wish to call attention to is, however, mainly the fact that the apparatus and technic that they use is that which is suitable to carbon dioxide alone and is wasteful, expensive and often inadequate with the mixed gases. If the mixed gases are to be administered, an apparatus of the type of the H. H. inhalator, such as the rescue crews use in carbon monoxide cases, is best. With it all the gas is inhaled, yet without any rebreathing.

To the Editor:— InThe Journal, July 25, pages 267-269, in an article entitled Hyperventilation in Abdominal Surgery, Dr. T. J. Ryan concludes that dioxide is of no value in the prevention of postoperative pneumonia. This conclusion is drawn from a group of 135 cases in which, at the close of abdominal operations, carbon dioxide was administered only once, for about three minutes, and a control group of 276 in which carbon dioxide was not administered. The morbidity is reported as 2.2 per cent for those who received the inhalation and 1.4 per cent for those who did not, and the mortality as 0.74 per cent for those treated and 0.36 per cent for those who were not. Obviously, if these figures are significant they indicate, not merely that carbon dioxide is without value in the prevention of postoperative pneumonia, but rather that this treatment tends to increase the

Effect of hyperthermia and Pa CO2 on the slowly adapting pulmonary stretch receptor.

Scientific evidence about the seriousness of the climate threat to agriculture is now unambiguous, but the ex- act magnitude is uncertain because of complex interactions and feedback processes in the ecosystem and the economy. Climate-related factors that would affect agricultural productivity in coming decades are: changes in temperature, precipitation, carbon dioxide (CO ), fertilization, short-term weather variability and surface water 2 run-off. Simulation of future climate in India under A2 scenario by IITM, Pune and Hadley Centre, UK, indicate that during the last quarter of present century the country will experience an increase in mean annual tempera- ture by 3-5C. Summer monsoon rainfall will increase by 20%, and extreme rainfall events would rise sharply in western and south-central parts. However, the arid western Rajasthan and the adjoining Punjab and Haryana will possibly experience notable decline in summer monsoon, and slight increase in winter rainfall, with pro- nounced variability in rainfall and fewer rainy days. Consequently, there will be higher incidence of droughts and floods in arid western India, affecting both rainy ( kharif) and winter ( rabi) season crops. Since a number of high- value crops are grown during the rabi, the negative impact on farmers economy would possibly be higher. Change in CO concentration too can show uncertainty in crop yields, but studies on the interrelationship be- 2 tween changes in rainfall, temperature and CO concentration and their effect on yield changes are quite few. 2 Adaptation and mitigation strategies to address the impact of climate change on agriculture are needed ur- gently through new research and proper interpretation of the accumulated research results from the decades of dryland research under different agro-climatic settings. Use of alternative crops or cultivars adapted to the likely changes, alteration in the planting date, and management of plant spacing and input supply might help in re- ducing the adverse impact. Use of resource-conservation technologies and a shift from sole cropping to diversi- fied farming system is highly warranted. Horticulture and agro-forestry need to be given more encouragement. Enabling policies on crop insurance, subsidies and pricing related to water and energy uses need to be strengthened at the earliest. Policies that would encourage farmers to enrich organic matter in the soil need emphasis. Also, it is necessary to develop a robust early warning system of spatio-temporal changes in weather as well as other environmental parameters. Contingency crop planning will require greater attention. Long-term strategic approaches to efficiently conserve and utilize rain water on the one hand and in-season tac- tical approaches to mitigate the adverse effects of weather aberrations on the other are also needed. Consider- ation of depletion rate of soil water is more important when the crops are grown primarily on stored soil water. Under such situations, wide rows and low plant populations are highly desirable. Water-conservation practices will become economically feasible when nutrient deficiencies are also corrected. Late onset of monsoon rains often leads to delayed planting and specific crop contingency plans have been developed for different agro-cli- matic zones to address the issue.

Выполнены измерения чистого экосистемного обмена (NEE) на мочажинном участке грядовомочажинного комплекса олиготрофного болота «Мухрино» с разделением на составляющие компоненты: валовую первичную продукцию (GPP) и дыхание экосистемы (R eco ). Измерения проводились в течение самого тёплого (июль), переходного (сентябрь) и самого холодного (октябрь) месяцев летне-осеннего сезона методом автоматизированных камер с 30-минутным интервалом. Это позволило получить подробную информацию о суточном ходе и сезонной динамике показателей. Для исследованных месяцев по отдельности и полевого сезона в целом осуществлен корреляционный анализ связи между гидрометеорологическими параметрами и величиной потоков. Для дыхания экосистемы (R eco ) наиболее высокий уровень корреляции за сезон выявлен с температурой почвы (0.88), температурой воздуха (0.71) и уровнем болотных вод (-0.73); за июль наиболее сильная корреляция выявлена с температурой воздуха (0.70) и температурой почвы (0.68); за сентябрь -с температурой почвы (0.81) и уровнем болотных вод (-0.78); за октябрь -с фотосинтетически активной радиацией (-0.59). Валовая первичная продукция (GPP) сильнее всего коррелирует с фотосинтетически активной радиацией (PAR) -в июле коэффициент корреляции равен -0.95, в сентябре -0.86, в октябре -0.79, в целом за полевой сезон -0.89. Чистый экосистемный обмен (PAR), аналогично GPP, наиболее тесно связан с PAR. В июле коэффициент корреляции NEE и PAR составляет -0.91, в сентябре -0.74, в октябре -0.71, за весь полевой сезон -0.73. Стоит подчеркнуть, что для каждого рассматриваемого месяца влияние внешних факторов на потоки уменьшается с течением времени от июля к октябрю, достигая минимума корреляции в самом холодном месяце. Ключевые слова: Дыхание экосистемы (R eco ); валовая первичная продукция (GPP); чистый экосистемный обмен (NEE); фотосинтетически активная радиация (PAR); LI-8100A; уровень грунтовых вод (WTL); автоматические камеры; Мухрино; болотные экосистемы Западной Сибири; круговорот углерода. Global climate change is one of the most important and promising phenomena to study in actual time. One of the key causes of global climate change is increasing the greenhouse gas (GHG) concentrations in the atmosphere [IPCC, 2023]. The main greenhouse gases are methane, carbon dioxides and nitric oxide, which contribute to the greenhouse effect and global warming [Lashof, Ahuja, 1990] . Carbon dioxide (CO 2 ) is one of the most significant and widespread gases involved in the planet's global carbon cycle [Lashof, Ahuja. 1990] . At the same time, living organisms play a key role in creation of atmosphere composition. Autotrophic organisms use a carbon dioxide to build their body structures, including complex organic compounds. During ecosystem functioning, the part of the carbon dioxide is released into the atmosphere through organism respiration, while another part is released through the decomposition of dead organic matter. Carbon dioxide may also be produced through natural and anthropogenic processes. Peatland ecosystems play a significant role in the planet's carbon cycle, both locally and globally. Peatlands in their natural undisturbed state are a significant long-term carbon sink 1 . However, the process of carbon deposition is not constantin different years, peatlands may serve either as carbon sink or source 2 . The main factor stimulating the carbon sequestration by peatland ecosystems is climatic conditions [Harenda et al., 2018; Bond-Lamberty et al., 2018] . Peatlands are the second most significant carbon stock on Earth and the largest on land. Despite covering only 2.84% of the Earth's land surface, the amount of soil organic carbon stored in them accounts for about one-third of all soil organic carbon on Earth. Peatlands in the northern hemisphere play a particularly important role in carbon sequestration, with an estimated accumulated carbon quantity of ~473-621 Gt of carbon [Yu et al., 2010] . The largest area of peatlands in Russia is located in Western Siberia, estimated at ~42% of the total Russian area [Vomperskiy et al., 1994; Sheng et al., 2004]. The territory of Western Siberia is featured to a high share of peatlands in original undisturbed state, making them an ideal location to study the impact of global changes on peatland biogeochemical functioning worldwide. The carbon balance of peatlands is mainly determined by two processes: photosynthesis and respiration [Harenda et al., 2018] . The main factors influencing the CO 2 flux from peatlands are photosynthetically active radiation, atmospheric air temperature (T avg ), soil temperature (T soil ), and water table level (WTL) [Miao et al., 2013;

To the Editor: Three cases of carbon dioxide rebreathing without a significant color change in the appearance of the canisters were experienced during general anesthesia with the same model anesthesia machines; Aestiva/5 (Datex Ohmeda, Wisconsin, USA) with a fresh gas flow of 1–2 l/min. Carbon dioxide rebreathing was recognized because the inspiratory carbon dioxide baseline of the capnogram trace gradually rose. The inhalational carbon dioxide concentration decreased immediately after increasing the fresh gas flow, and rose again with decreasing the fresh gas flow. This indicates that carbon dioxide rebreathing was due to carbon dioxide accumulation in the semi-closed circuit system of the anesthesia machines. A color change in the appearance of the carbon dioxide absorbent was recognized only in the upper part of the canister (Fig. 1a). The top surface of the canister showed a significant color change limited to the middle part of it (Fig. 1b). The section image of the canister showed a significant columnar color change of the carbon dioxide absorbent along the full length of the center part of it (Fig. 1c). The observation of the canister bottom of Aestiva/5 revealed that only the center part of it had the mesh part for the exhaled gas, and the color change of the carbon dioxide absorbent seemed to accord with the mesh part of the bottom (Fig. 1d). As an experiment, when a transparent plastic partition wall was settled in the canister before filling with carbon dioxide absorbent, the columnar color change was no longer visible. This indicated that the flow of the exhaled gas was influenced by the wall in the canister. Considering these results, it is supposed that the structural characteristic of the canister bottom of the anesthesia machine; Aestiva/5, caused channeling and the inhomogeneity of the current of inhaled gas in the canister led to the columnar color change of the carbon dioxide absorbent. The role of the carbon dioxide absorbent canister becomes more important as the fresh gas flow quantity decreases. A technique of using a fresh gas flow of 1 l/min was reported first in 1952 [1]. The technique with the fresh gas flow less than 1 l/min subsequently became known as ‘‘low-flow anesthesia’’. Afterwards, a technique using a fresh gas flow of 500 ml/min was reported as ‘‘minimal flow anesthesia’’ [2]. These cases of carbon dioxide rebreathing without significant color change in the appearance of the canisters provide very important information not only for anesthesiologists, but also for all persons using anesthesia machines. When carbon dioxide rebreathing is recognized, carbon dioxide accumulation in the circuit system of the anesthesia machines should be suspected and exhaustion of the carbon dioxide absorbent should be immediately T. Yamamoto (&) Department of Pediatric Anesthesiology and Critical Care Medicine, Children’s Hospital Asklepios Klinik Sankt Augustin, Arnold-Janssen-Str. 29, 53757 Sankt Augustin, Germany e-mail: yamatomo270@hotmail.com; t.yamamoto@asklepios.com

The formation of the cyclic carbon trioxide isomer, CO3(X 1A1), in carbon-dioxide-rich extraterrestrial ices and in the atmospheres of Earth and Mars were investigated experimentally and theoretically. Carbon dioxide ices were deposited at 10 K onto a silver (111) single crystal and irradiated with 5 keV electrons. Upon completion of the electron bombardment, the samples were kept at 10 K and were then annealed to 293 K to release the reactants and newly formed molecules into the gas phase. The experiment was monitored via a Fourier transform infrared spectrometer in absorption-reflection-absorption (solid state) and through a quadruple mass spectrometer (gas phase) on-line and in situ. Our investigations indicate that the interaction of an electron with a carbon dioxide molecule is dictated by a carbon–oxygen bond cleavage to form electronically excited (1D) and/or ground state (3P) oxygen atoms plus a carbon monoxide molecule. About 2% of the oxygen atoms react with carbon dioxide molecules to form the C2v symmetric, cyclic CO3 structure via addition to the carbon–oxygen double bond of the carbon dioxide species; neither the Cs nor the D3h symmetric isomers of carbon trioxide were detected. Since the addition of O(1D) involves a barrier of a 4–8 kJ mol−1 and the reaction of O(3P) with carbon dioxide to form the carbon trioxide molecule via triplet-singlet intersystem crossing is endoergic by 2 kJ mol−1, the oxygen reactant(s) must have excess kinetic energy (suprathermal oxygen atoms which are not in thermal equilibrium with the surrounding 10 K matrix). A second reaction pathway of the oxygen atoms involves the formation of ozone via molecular oxygen. After the irradiation, the carbon dioxide matrix still stores ground state oxygen atoms; these species diffuse even at 10 K and form additional ozone molecules. Summarized, our investigations show that the cyclic carbon trioxide isomer, CO3(X 1A1), can be formed in low temperature carbon dioxide matrix via addition of suprathermal oxygen atoms to carbon dioxide. In the solid state, CO3(X 1A1) is being stabilized by phonon interactions. In the gas phase, however, the initially formed C2v structure is rovibrationally excited and can ring-open to the D3h isomer which in turn rearranges back to the C2v structure and then loses an oxygen atom to ‘recycle’ carbon dioxide. This process might be of fundamental importance to account for an 18O enrichment in carbon dioxide in the atmospheres of Earth and Mars.

Acid tests

Intraabdominal fire during laparoscopic cholecystectomy.

Forsøg på rekonstruktion af en fortidig jernudvindingsproces

Capnography: Clinical Aspects.

This paper records the effects of carbon dioxide when used for euthanasia, on behaviour, electrical brain activity and heart rate in rats. Four different methods were used. Animals were placed in a box (a) that was completely filled with carbon dioxide; (b) into which carbon dioxide was streamed at a high flow rate; (c) into which carbon dioxide was streamed at a low flow rate and (d) into which a mixture of carbon dioxide and oxygen was streamed at a fast rate. It was found that the cessation of behaviour was associated with an aberrant pattern of electrical brain activity together with an abnormally low heart rate. The time to reach this point was shortest in those animals placed in the box filled with pure carbon dioxide, longer when carbon dioxide was introduced at a high rate into the box, longer still when oxygen was added to the carbon dioxide gas, and longest when carbon dioxide was streamed slowly into the box. In the condition with pure carbon dioxide, signs of behavioural agitation and asphyxia were seen. This was also true for the two conditions in which carbon dioxide streamed into the box, but to a lesser degree. These signs occurred when some degree of consciousness may still have been present in the animals. Signs of agitation and asphyxia were almost completely absent in the condition where oxygen was added to the carbon dioxide. These results not only demonstrate the usefulness of behavioural criteria next to electrophysiological indices, but also demonstrate that the negative effects of carbon dioxide euthanasia can be prevented by an additional supply of oxygen.

Coupling model for carbon dioxide wellbore flow and heat transfer in coiled tubing drilling

The zonally averaged response of the Global Change Research Center two‐dimensional (2‐D) statistical dynamical climate model (GCRC 2‐D SDCM) to a doubling of atmospheric carbon dioxide (350 parts per million by volume (ppmv) to 700 ppmv) is reported. The model solves the two‐dimensional primitive equations in finite difference form (mass continuity, Newton's second law, and the first law of thermodynamics) for the prognostic variables: zonal mean density, zonal mean zonal velocity, zonal mean meridional velocity, and zonal mean temperature on a grid that has 18 nodes in latitude and 9 vertical nodes (plus the surface). The equation of state, p=ρRT, and an assumed hydrostatic atmosphere, Delta;p=−ρgΔz, are used to diagnostically calculate the zonal mean pressure and vertical velocity for each grid node, and the moisture balance equation is used to estimate the precipitation rate. The model includes seasonal variations in solar intensity, including the effects of eccentricity, and has observed land and ocean fractions set for each zone. Seasonally varying values of cloud amounts, relative humidity profiles, ozone, and sea ice are all prescribed in the model. Equator to pole ocean heat transport is simulated in the model by turbulent diffusion. The change in global mean annual surface air temperature due to a doubling of atmospheric CO2 in the 2‐D model is 1.61 K, which is close to that simulated by the one‐dimensional (1‐D) radiative convective model (RCM) which is at the heart of the 2‐D model radiation code (1.67 K for the moist adiabatic lapse rate assumption in 1‐D RCM). We find that the change in temperature structure of the model atmosphere has many of the characteristics common to General Circulation Models, including amplified warming at the poles and the upper tropical troposphere, and stratospheric cooling. Because of the potential importance of atmospheric circulation feedbacks on climate change, we have also investigated the response of the zonal wind field to a doubling of CO2 and have found distinct patterns of change that are related to the change in temperature structure. In addition, we find that both the global mean kinetic energy and simulated Hadley circulation increase when CO2 is doubled. The increase in mean kinetic energy is a result of the increase in upper level meridional temperature gradients simulated by the model. It is stressed that changes in atmospheric dynamics associated with increased carbon dioxide may also be very important to the final steady state distribution of such greenhouse gases as ozone and water vapor. Hence further research in this regard is warranted.