Google's Triangle app will help users to Save Mobile Data

Melbourne, Jul 24: Home-made cloth face masks may need a minimum of two layers, and preferably three, to prevent the dispersal of viral droplets associated with Covid-19, according to a study.

Researchers, including those from the University of New South Wales in Australia, noted that viral droplets are generated by those infected with the novel coronavirus when they cough, sneeze, or speak.

As face masks have been proven to protect healthy people from inhaling infectious droplets as well as reducing the spread from those who are already infected, several types of material have been suggested for these, but based on little or no evidence of how well they work, the scientists said.

In the current study, published in the journal Thorax, the researchers compared the effectiveness of single and double-layer cloth face coverings with a surgical face mask (Bao Thach) at reducing droplet spread.

They said the single layer covering was made from a folded piece of cotton T shirt and hair ties, and the double layer covering was made using the sew method described by the US Centers for Disease Control and Prevention (CDC).

The scientists used a tailored LED lighting system and a high-speed camera to film the dispersal of airborne droplets produced by a healthy person with no respiratory infection, during speaking, coughing, and sneezing while wearing each type of mask.

Their analysis showed that the surgical face mask was the most effective at reducing airborne droplet dispersal, although even a single layer cloth face covering reduced the droplet spread from speaking.

But the study noted that a double layer covering was better than a single layer in reducing the droplet spread from coughing and sneezing.

According to the researchers, the effectiveness of cloth face masks is dependent on the number of layers of the covering, the type of material used, design, fit as well as the frequency of washing.

Based on their observations, they said a home made cloth mask with at least two layers is preferable to a single layer mask.

"Guidelines on home-made cloth masks should stipulate multiple layers," the scientists said, adding that there is a need for more research to inform safer cloth mask design.

New Delhi, Mar 7: The Union government has issued a Global Invite for Expression of Interest for disinvestment in Bharat Petroleum Corporation Limited (BPCL) from prospective bidders with a minimum net worth of $10 billion as of Saturday.

The EoI submissions can be made till May 2, whereas investor queries will be entertained till April 4.

Another condition pertains to a maximum of four members are permitted in a consortium, and the lead member must hold 40 per cent in proportion. Other members of the consortium must have a minimum $1 billion net worth.

The EOI allows changes in the consortium within 45 days, though the lead member cannot be changed.

The GoI proposes to disinvest its entire shareholding in BPCL comprising 1,14,91,83,592 equity shares held through the Ministry of Petroleum and Natural Gas, which constitutes 52.98 per cent of BPCL's equity share capital, along with the transfer of management control to the strategic buyer (except BPCL's equity shareholding of 61.65 per cent in Numaligarh Refinery Limited (NRL) and management control thereon).

The shareholding of BPCL in NRL will be transferred to a Central Public Sector Enterprise operating in the oil and gas sector under the Ministry and accordingly is not a part of the proposed transaction.

May 30: Patients undergoing surgery after contracting the novel coronavirus are at an increased risk of postoperative death, according to a new study published in The Lancet journal which may lead to better treatment guidelines for COVID-19.

In the study, the scientists, including those from the University of Birmingham in the UK, examined data from 1,128 patients from 235 hospitals from a total of 24 countries.

Among COVID-19 patients who underwent surgery, they said the death rates approach those of the sickest patients admitted to intensive care after contracting the virus.

The scientists noted that SARS-CoV-2 infected patients who undergo surgery, experience substantially worse postoperative outcomes than would be expected for similar patients who do not have the infection.

According to the study, the 30-day mortality among these patients was nearly 24 per cent.

The researchers noted that mortality was disproportionately high across all subgroups, including those who underwent elective surgery (18.9 per cent), and emergency surgery (25.6 per cent).

Those who underwent minor surgery, such as appendicectomy or hernia repair (16.3 per cent), and major surgery such as hip surgery or for colon cancer also had higher mortality rates (26.9 per cent), the study said.

According to the study, the mortality rates were higher in men versus women, and in patients aged 70 years or over versus those aged under 70 years.

The scientists said in addition to age and sex, risk factors for postoperative death also included having severe pre-existing medical problems, undergoing cancer surgery, undergoing major procedures, and undergoing emergency surgery.

"We would normally expect mortality for patients having minor or elective surgery to be under 1 per cent, but our study suggests that in SARS-CoV-2 patients these mortality rates are much higher in both minor surgery (16.3%) and elective surgery (18.9%)," said study co-author Aneel Bhangu from the University of Birmingham.

Bhangu said these mortality rates are greater than those reported for even the highest-risk patients before the pandemic.

Citing an example from the 2019 UK National Emergency Laparotomy Audit report, he said the 30-day mortality was 16.9 per cent in the highest-risk patients.

Based on an earlier study across 58 countries, Bhangu said the 30-day mortality was 14.9 per cent in patients undergoing high-risk emergency surgery.

"We recommend that thresholds for surgery during the SARS-CoV-2 pandemic should be raised compared to normal practice," he said.

"For example, men aged 70 years and over undergoing emergency surgery are at particularly high risk of mortality, so these patients may benefit from their procedures being postponed," Bhangu added.

The study also noted that patients undergoing surgery are a vulnerable group at risk of SARS-CoV-2 exposure in hospital.

It noted that the patients may also be particularly susceptible to subsequent pulmonary complications, due to inflammatory and immunosuppressive responses to surgery and mechanical ventilation.

The scientists found that overall in the 30 days following surgery 51 per cent of patients developed a pneumonia, acute respiratory distress syndrome, or required unexpected ventilation.

Nearly 82 per cent of the patients who died had experienced pulmonary complications, the researchers said.

"Worldwide an estimated 28.4 million elective operations were cancelled due to disruption caused by COVID-19," said co-author Dmitri Nepogodiev from the University of Birmingham.

"Our data suggests that it was the right decision to postpone operations at a time when patients were at risk of being infected with SARS-CoV-2 in hospital," Nepogodiev said.

According to the researchers, there's now an urgent need for investment by governments and health providers in to measures which ensure that as surgery restarts patient safety is prioritised.

They said this includes the provision of adequate personal protective equipment (PPE), establishment of pathways for rapid preoperative SARS-CoV-2 testing, and consideration of the role of dedicated 'cold' surgical centres.